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Geology Field Trip Destinations in San Diego County

This website lists selected field trip destinations available for students in for geology, earth science, and oceanography classes at MiraCosta College in northern San Diego County. Some field trips (below) may be scheduled during class time - some for Oceanside campus classes; some for San Elijo campus classes.

Other field trips are scheduled for dates on Fridays and Weekends. Students are not obligated to attend of these trips, but they may count for assignment credit for those who attend (instructor's choice).

Note that potential hazards exist on any field trip. Traveling to the site of the field trip is perhaps the greatest risk. Common hazards on field trips include sun burn, heat exhaustion, tripping and falling, insect bites, and exposure to poison oak and other allergens. Rattlesnakes and other wildlife can be encountered practically anywhere, especially along nature trails.

Click on images for a larger view.
Map of fieldtrip destinations Map of field trip destinations in coastal San Diego County/
Warning about Beach Hazards

Please note! The beach is a most dangerous field trip destination. Plan ahead and check to be sure it is LOW TIDE before planning a trip to the beach localities listed below.

Be aware that it is never safe to go near the base of actively-eroding sea cliffs, and it is always important to be wary of rouge waves, strong currents, and dangerous surf conditions. If you feel a strong earthquake, get off the beach immediately!
Rock Fall
Geologic Maps and Topographic Maps of Coastal San Diego County

Oceanside 1:100,000 scale map and 1:24,000 scale maps (coastal northern San Diego County)

San Diego 1:100,000 scale map and 1:24,000 scale maps (coastal southern San Diego County)

These maps were modified from California state and federal geologic maps - very useful resources for studying regional geology! Use these maps to research information about where you live, and the locations of places you plan to hike or observe nature.
Geologic Map index for Oceanside 1::100,000 scale map.Oceanside geologic quadrangle map index
San Diego geologic quadrangle map index
Geologic Map Exercise
(coming soon!)

Coast Destinations

Field trip destinations along the San Diego Coastline are described below starting in the south.

Cabrillo National Monument

Cabrillo National Monument occupies the south end of the Point Loma Peninsula and provides a scenic view of San Diego Bay and downtown San Diego. The park has a visitor center and several trails. A popular destination is the Tide Pools area, not only for the exceptional marine life viewing, but also the spectacular geologic setting. Tilted rock layers of the Cretaceous-age Point Loma Formation are exposed in the lower sea cliffs near the tide pools area. These rocks from sediments deposited on deep-sea fans (originally thousands of feet below sea level). Tectonic forces pushed them up. These titled layers are unconformably overlain by younger Miocene age sedimentary deposit that locally contain large boulders of many kinds rocks (ancient river deposits).

It is highly recommend to check the Cabrillo National Monument website before planning a trip to the park. A National Park Service brochure recommends not going here on weekends or holidays due to road closure and parking limitations. You might want to call in advance to see what conditions are like at the tide pool area.

Life in the Rocky Intertidal Zone

This brochure identifies many of the local benthic life forms found in the tide pools.
Cabrillo NM region
Map of Point Loma showing Cabrillo National Monument
Cabrillo NM
Park road and trail map of Cabrillo National Monument
Cabrillo Stature
Statue of Cabrillo on Point Loma.

View of San Diego Bay from Point Loma Visitor Center
Sea cliff near tide pools area
Dipping beds of Cretaceous Point Loma Formation
Tide pools area in Cabrillo National Monument
Tide pools area at Cabrillo National Monument.

Point La Jolla and La Jolla Bay

The urban area of La Jolla is at the north end of the La Jolla Peninsula. Hard sandstone bedrock of Cretaceous-age Point Loma Formation. The seacliffs and small sandy bays along the La Jolla Coast are a scenic destination for tourists. La Jolla Cove, located just east of Point La Jolla, is host to a growing seal and sea lion population. La Jolla Cove is perhaps most famous for its seven sea caves. The caves are accessible by kayak, snorkeling, or wet hiking during low tide. It is important to check weather and tide conditions before attempting a visit.
Map of the La Jolla Cove area
Map of La Jolla showing the locations of La Jolla Bay and La Jolla submarine canyon.
View of La Jolla Caove from Birch Aquarium pateo area.
View looking south at La Jolla Bay as seen from the outdoor patio area at the Birch Aquarium. Marine terraces give a step-like appearance between the coast and the high point at Mt. Soledad in the La Jolla upland.

Birch Aquarium - Scripps Institute of Oceanography

The Birch Aquarium and Museum is affiliated with the Scripps Institute and the University of California at San Diego in La
Jolla. The aquarium houses a 70,000-gallon tank of sea life and interactive aquatic displays. The aquarium has dozens of aquariums representing sea life from around the world and locally. The aquarium staff are constantly revising special exhibits relating to the effect of human activity and climate change on the world's oceans. There is a large man-made tide pool full of "touchable" specimens on an outdoor patio. Note that the aquarium is very popular for school groups during daytime hours.

Visit the Birch Aquarium website.

For discounted tickets for Birch Aquarium for college students: Click here
Whale statue in front of Birch Aquarium

Dike Rock Volcanic Area and Tide Pools

Dike Rock is a volcanic feature composed of a black, basaltic-andesite dike. About 11 million years ago, magma rose to the surface along a fracture zone in older Tertiary sedimentary rocks. The dike, and associated tide pool area, is located about a half mile (600 meters) north of the Scripps Institution of Oceanography pier. The massive sea cliffs between the pier and Dike Rock display very interesting sedimentary features in beds of sandstone and conglomerate that grow increasingly coarser-grained to the south.
Dike Rock tide pool area north of Scripps Pier. Map showing location of Dike Rock.

Torrey Pines State Nature Preserve

Torrey Pines is a wonderful place to spend a day hiking and checking out the sea cliffs and beaches. This 2,000 acre park is dedicated to preserving the rare Torrey Pine and coastal shrub habitat. The sea cliffs are a nesting area for peregrine falcons. Parking is free along the beach, but is usually packed early. Fee parking is available at the State Park lots.

Torrey Pines is also famous for its well-exposed geology. The 372 foot elevation of the ridgeline is on the the west side of the Rose Canyon Fault system (a regionally active earthquake fault) that runs offshore beneath the baymouth bar at the mouth of Los Penasquitos Lagoon (north end of the preserve). Small faults can be seen in the road cut along N. Torrey Pines Road.

Three rock formations are exposed in the sea cliffs and hill tops in the Torrey Pines area (oldest to youngest, respectively).
The Del Mar Formation of Eocene age (about 45 to 48 million years old). The Delmar Formation consists mostly of sandstone and a greenish clay mineral called glauconite). The Del Mar Formation locally contains an abundance of marine fossils, mostly oyster, clams, and gastropods (snails). The sediment was deposited in a shallow continental-shelf setting.

The Torrey Sandstone or Torrey Formation unconformably overlies the Del Mar Formation and is also of Eocene age (about 40 million years) and consists of massive sandstone, mostly of beach and offshore sand bar deposits. In the sea cliffs the Torrey Formation sands out as white or buff-colored cliffs. On the higher seacliffs, the Torrey Sandstone displays unusual taphoni-style weathering giving the rocks a pitted or cave-like appearance.

The Bay Point Formation is the youngest rock formation exposed along the ridge at the top of the cliffs is possibly less than a million years old. The Bay Point formation is locally full of gravel, well-rounded beach cobbles (and is the source of the gravel on the area beaches).

Visit the park's websites: TorreyPines.org.
Geology: This link describes rock formations, cliffs, erosion, fossils, faults, and marine terraces.
Seashore and Ocean: this link describes rocky shore biota, sandy shore biota, marine mammals, Flat Rock, and Los Penasquitios Lagoon. Plan to hike up to the Visitor Center and cliff bluff trails for exceptional views.
Torrey Pines Map Map showing the location of Torrey Pines State Nature Preserve.

View looking south toward Torrey Pines Beach.
View looking south at Torrey Pines Beach from near the Amtrak Railroad Overpass Bridge on N. Torrey Pines Road.
View of Black's Beach ffrom the Glider Port overlook.
View looking north from the Glider Port over Black's Beach and the sea cliffs at the south end of Torrey Pines State Nature Preserve.
Faults exposed along N. Torrey Pines Road.
Young faults cut through Torrey Sandstone and overlying Bay Point Formation along N. Torrey Pines Road near the park. The Rose Canyon Fault is nearby.
Rock formations exposed in sea cliff at Torrey Pines Beach.
Green beds consist of the Del Mar Formation (about 45 million) overlain by red bed of the Torrey Sandstone (about 40 million years old).
Upland plant community in Torrey Pines State Nature Preserve. Torrey Pines and coastal shrub crop out on the ridge, growing mostly on the sand and gravel-rich deposits of Bay Point Formation (Quaternary age).

Del Mar Dog Beach

Del Mar Dog Beach is an exceptional place to examine sea cliffs, coastal erosion, Eocene-age rock formations with fossils, and wave tidal processes shaping the entrance to San Dieguito Lagoon. There is hourly parking along the Coast Highway (101), but there is also free parking on Via de la Valle Road near the intersection with the Coast Highway near the park. This is an off-leash dog area, and is a lot of fun to watch the dogs (and people). However, running groups of dogs can crash into you. If you have a fear of dogs, don't attend this field trip. Plan to go at LOW TIDE only! The beach below the sea cliffs many be inaccessible during low tide. There may be strong rip tides near the mouth of the lagoon. See Del Mar Tides information to plan a trip. Yes you can bring your dog! Dogs can be off leash after Labor Day to Memorial Day. A trial leads up stairs to North Beach Overlook which provides an excellent view south to La Jolla's marine terraces.

Rock formations exposed in the sea cliffs include the Del Mar Formation (Eocene), Torrey Sandstone (Eocene), and Bay Point Formation (Quaternary) - these formations are the same as those exposed in Torrey Pines State Nature Preserve (above).
Del Mar Dog Beach MapMap of North Point Park and Del Mar Dog Beach
View of sea cliff and beach at Del Mar Dog Beach at low tide.
North Beach headlands at the Del Mar Dog Beach.
Del Mar Dog Beach at high tide.
Del Mar Dog Beach at high tide.
Fossil oysters in sandstoe
Fossil oyster shells in the Del Mar Formation.
Areal view of the tidal delta at Del Mar Dog Beach
The tidal delta at Del Mar Dog Beach. This aerial view shows low tide at the mouth of the San Dieguito River lagoon.

Solana Beach

Fletcher Cove provides beach access to Solana Beach: Lots of sea wall construction, good examples of bluff failure due to wave attack on faults and joints. Walking north you’ll pass a near continuous stretch of seawalls (dubbed “Solana Wall” by Surfrider); walking south you’ll pass seawalls, concrete plugs, and stretches of exposed bedrock (mostly Torrey Sandstone in this area). There are interesting geologic exposures of unconformities and paleo-valley fill deposits exposed in the sea cliff at Fletcher Cove.

Seaside Beach access, Solana Beach: This a is a half-mile north of Fletcher Cove, so if you walk south you see Solana Wall, and if you go north you see some older failing walls and plugs. Depending how much walking you want students to do, you could take in both areas above.

Angular unconformity at Fletcher Cove beach.
An angular unconformity in the sea cliff at Fletcher Cove.
Fletcher Cove Map
Location map of Fletcher Cove in Solana Beach

San Elijo Lagoon and San Elijo State Beach

San Elijo Lagoon Nature Center - This is also near the San Elijo Campus. The theme here is how lagoon valley formed over time and how marine terrace formation are connected to sea level changes. Across the lagoon on the south side you can see several marine terraces, rising in elevation inland, all built up with houses. A short walking trail from the interpretive nature center takes you out into the lagoon where both coastal plants and animal life are commonly accessible.

Annie's Canyon and N. Rios Trailhead Access to San Elijo Lagoon South Shore and Annie's Canyon (a slot canyon in the Torrey Sandstone).

San Elijo State Beach
is the closest beach to MiraCosta College San Elijo Campus. Take Manchester Avenue west (past I-5) and continue when it becomes San Elijo Avenue. There is ample free parking along the road where San Elijo Avenue crosses Chesterfield Drive. Park and wall across the bridge over the train railroad tracks and cross the Coast Highway at the stop light. Enter the park at the trail near the "Cardiff Kook" statue. Cross the campground at San Elijo State Beach and take the stairs down to the beach. The field trip is to examine the sea cliff, processes forming the beach, and the entrance (tidal delta) to the San Elijo Lagoon. Plan to go at LOW TIDE only! The beach below the sea cliffs many be inaccessible during high tide. There may be strong rip tides near the mouth of the lagoon.
Map showing locations around San Elijo Lagoon.
Map of San Elijo Lagoon and San Elijo State Beach (in Cardiff). The map show the trailhead on the south side of the lagoon, the location of the Nature Center, and San Elijo beach near the mouth of the lagoon.
Topographic map of San Elijo Lagoon area.
Topographic map of San Elijo Lagoon (before construction of MiraCosta College campus)
Tide channel in San Elijo Lagoon
View of the tidal creek from near the San Elijo Lagoon Nature Center along Manchester Rd.
View of San Elijo Lagoon form the south shore.
View of San Elijo Lagoon as seen from the south side of the valley.
Students in Annie's Canyon (slot canyon)
Annie's Canyon (a slot canyon carved in Torrey Sandstone)
View looking south along San Elijo Beach in the fog.
View of San Elijo State Beach (looking south) on a foggy morning.
View of man standing next to sea cliff showing sedimentary structures.
Soft sedimentary beds bearing desiccation cracks preserved in ancient lagoon deposits.
Bedrock exposed on a wave-cut bench at San Elijo State Beach.
Wave-cut platform at low tide (missing beach sand) exposing the Eocene Del Mar Formation
Sunset at San Elijo State Beach near mouth of tidal creek.
Sunset surfers on the tidal delta at the mouth of San Elijo Creek.

Encinitas Beaches and Sea Cliffs

Encinitas is famous for its beaches and seacliffs, somewhat notoriously. The coastal community in Encinitas has been experiencing a long-protracted battle fighting the effects of coastal erosion. The area is constantly loosing sand that was naturally provided by streamflow and sea cliff erosion in the past. Home build, often precariously close to the cliff end are under constant threat of slumping and sea cliff collapse due to the undercutting of the waves. In addition sand has to be replenished after winters with strong storm wave action that move sand offshore and down the coast. Many homeowners, at their own expense, have crafted sea walls in attempts to protect their homes. The California Coastal Commission has upgraded construction rules for seawalls in an attempt to maintain a scenic character to the seacliffs. A wall along the beach (at low tide) gives a visitor a view of the quality and success of their efforts to protect their valuable views and real estate.
Bedrock and tide pools exposed at Swamis State Beach.
Beach rock exposures with small tide pools on Swamis State Beach
Sand bars exposed at a low King Tide at Moonlight Beach.
View from D Street Stairs of of beach at low King Tide.
Sea cliff and sea walls at Encinitas Beach.Sea cliffs with sea walls protecting homes from beach erosion View looking south from stairs at Beacons Beach.
View looking south from Beacons Beach stairs.
Panarama view of Moonlight Beach in Encinitas.
Panoramic view of Moonlight Beach located in a bay where Encinitas Creek enters the ocean.

Batiquitos Lagoon Nature Center and North Shore Nature Trail

Batiquitos Lagoon is another drowned river valley along the San Diego coastline. The small Batiquitos Lagoon Visitor Center has exhibits and orientation information about the lagoon. It is located at the head of a nature trail that runs along the north shore of the lagoon. The eastern end of the lagoon trail is fairly quite (far from the highway) and typically supplies an abundance of wildlife viewing. There is a 20-stop guide to the trail available in the visitor center. It is an easy trail with lots of shade trees and is a popular place for hikers.
Map of Batiquitos Lagoon area.
Map of Batiquitos Lagoon

South Carlsbad State Beach

This is an excellent beach to study beach processes and sea cliff erosion. An erosional unconformity with a elevated marine terrace gravel on top is well exposed. Layered black sand beds are well exposed south of the parking area in the sea cliff. From MCC Oceanside Campus, the most direct route is the take Highway 78 west to I-5 South. Follow I-5 to the Palomar Airport Road Exit (Exit 47). Head west on Palomar Airport Road (careful to choose the correct lane to proceed toward Carlsbad Road South (you will be driving south with the seacliffs on your right). Proceed 1/2 mile to the parking area for South Carlsbad State Beach.
Panarama view of sea cliff at South Carlsbad State Beach.
Panoramic view of seacliffs and beach of South Carlsbad State Beach. Lower gray rock is Torrey Sandstone (Eocene age). Upper red beds are marine terrace deposits of the Bay Point Formation of Quaternary age..
Map of South Carlsbad State Beach
Map to South Carlsbad State Beach
A sea cave at South Carlsbad State Beach.
Fragile sea cave at the north end of the beach.
Gravel bar on South Carlsbad State Beach.
Beach gravel accumulates on the beach in winter season.
Black Sand layers at South Carlsbad State Beach.
Black sand layers exposed in sea cliff at south end of beach

Tamarack Beach, Carlsbad

: This is a field trip location for local oceanography lab classes. You have to approach by car from the north in order to park (along the beach side of Highway 101). The two pairs of jetties that bracket the beach illustrate the dominant southward longshore drift. The beaches are noticeably wider on the north sides of both jetties, and the beach between the jetties widens from north to south. The southward drift of sand regularly plugs the jetty entrances to Agua Hedionda Lagoon, requiring frequent dredging. This area is a good location for beach profiling excursions to measure seasonal changes in the beach. The outer bay of Agua Hedionda Lagoon is used for aquaculture (farm-raised oysters and mussels) and is the location of the Claude "Bud" Lewis Carlsbad Desalination Plant.
Tamarack Beach Map of Tamarack Beach and Agua Hedionda Lagoon.

Oceanside Pier and Oceanside Harbor

Oceanside Municipal Pier is one of the longest wooden piers on the West Coast, at 1,942-feet. Mostly a place for fishermen, tourists and residents, but is also a destination for local oceanography lab field trips. When conditions are right, the pier can be useful for studying wave periods, wave patterns, currents, beach erosion, local sea life, and shoreline management. There is plenty of parking but it's all pay. Watch how waves change as they slow and break. Looking down at the water within the surf zone often shows a longshore current, depending on swell direction. The Oceanside Jetty, visible in the distance to the north, is a major blocker of south-drifting sand, leading to sand depletion along North County beaches. A walk down the beach to the mouth of the San Luis Rey River and out and around Oceanside Harbor is a wonder way to spend a day!

Oceanside Harbor is a fully managed artificial harbor supporting the Camp Pendleton Marine Base and the boat storage and fishing community out of Oceanside. The harbor provides an interesting lesson in coastal dynamics and infrastructure. The harbor is subject to filling with sand from longshore drift, requiring occasional dredging to provide sand to the beach in Oceanside. The large rip-rap jetties are now host to hard-bottom marine communities (plants and animals). Seal, sea lions, and dolphins are a common sighting in and around the harbor.
Oceanside Pier and Harbor Map showing the locations of Oceanside Pier and Oceanside Harbor
View of Oceanside Pier from the north.
View looking south along Oceanside beach toward the Pier.
Beach erosion along Oceanside Beach.
View looking north from the Pier showing beach erosion after a winter storm.
Sea lions on a dock with kayaks in Oceanside Harborn.
Sea lions on a dock in Oceanside Harbor.
Rip-rap boulders covered with sea weed on Oceanside Jetty.
Algae grows in the intertidal zone on the rip-rap jetties.

Dana Point Harbor - Oceans Institute

Richard Henry Dana Jr. (1815-1882) was a Harvard-trained lawyer, a seaman, and an author of the classic sea journal, Two Years Before the Mast (1840). In his journal, Dana documents his voyage from Boston around Cape Horn to California on the merchant ship, the Brig Pilgrim, and account of what life and landscapes in the San Diego region looked like before our modern era. Dana describes the area once known as Capistrano Bay, also known as Dana Point.

The resistant rocky seacliffs at Dana Point consisted of the Early-Middle Miocene San Onofre Breccia. The breccia formation has been uplifted by faulting and forms the headland of Dana Point. The resistant headland at Dana Point, protects Capistrano Bay (now Dana Point Harbor).

Dana Point is home to the Ocean Institute, an organization dedicated to education programs about marine life, maritime history, and outdoor education. The Ocean Institute maintains two historic sailing ships. The educational programs are ideal for getting students out to sea!
A tall mast sailing ship in Dana Point Harbor.
The restored version of Brig Pilgrim in Dana Point Harbor

Map of Dana Point & Harbor

Hilltop view of Dana Point Harbor and Jetty.
Dana Point Harbor & Jetty

Inland Field Trip Destinations

Calavera Hills Volcano in Carlsbad

Calavera Hills Nature Preserve is an excellent field trip destination near the MiraCosta College Oceanside Campus. This open-space preserve park is host to an ancient volcano that erupted along the coast sometime between 13-18 million years ago. The internal features of the old volcano are exposed in a cut used to mine rock in the construction of Calavera Lake Dam.

Follow College Avenue south for about 1 mile (south of Highway 78). Turn left on Tamarack Avenue and follow the road down through the neighborhood until you see the trailhead that leads to the dam. The volcano is on the opposite side of the dam. There is much to examine here!
View of Calavera Hills volcano and reservoir dam.
The Calavera Hills volcano is the eroded remnant of a larger volcano. Its peak is the highest point in Carlsbad. The hard-rock core of the volcano was mined for construction of the dam.
Calavera Hills volcano
Location map of the Calavera Hills volcano.

San Marcos Mountains

Double Peak (elevation 1,644 feet) is the highest mountain in northern coastal San Diego County. The park located in the high peak area provides spectacular panoramic views in all directions. A short, easy walk connects the parking lot to the high peak. On a clear day it is possible to see distant snow-capped mountain ranges to the north (San Gabriel, San Bernardino, and San Jacinto Mountains), Palomar Mountain (ridge), and many other peaks and plateau regions of the Peninsular Ranges in San Diego County. The entire coastline from Dana Point (to the north) to Mexico, and many of the island offshore are visible on a clear day. Rocks exposed on Double Peak include ancient granite, basalt, and metamorphic rocks of Mesozoic age.
Map showing location of Double Peak Park and Elfin Forest Recreational Reserve.
Map showing locations of Double Peak Park and the Elfin Forest Preserve.
Panorama view from the top of Double Peak showing the region around San Marcos.
Panoramic view looking east to north from Double Peak Park, the high point in the San Marcos Mountains. The distant ridge on the right is Mount Palomar. The city of San Marcos occupies the valley. On a clear day it is possible to see the high peaks of the San Bernardo Mountains, San Jacinto Peak, and the crest of the high peaks of the San Diego Peninsular Range near Julian, offshore islands, and high peaks in Mexico.

Elfin Forest Recreational Reserve

The Elfin Forest Recreational Reserve covers 784 acres in the heart of the San Marcos Mountains. Olivenhain Reservoir was constructed in the middle of this mountainous upland to support the Olivenhain Municipal Water District in partnership with the San Diego County Water Authority and the US Bureau of Land Management. The Reserves offers approximately 11 miles of hiking, mountain biking, and equestrian trails, and exceptionally scenic mountain viewing points. The Reserve is host to oak riparian, oak woodland, coastal sage scrub, and chaparral plant communities.

The Elfin Forest Visitor Center is located on Elfin Forest Road where parking for the primary trailhead to the upland areas is located. The Botanical Trail is a 1.1 mile loop trail that starts near the visitor center. The Botanical Trail is an ideal location to learn about plant communities along Escondido Creek and the region. (Click on link to a brochure describing the 27 stops.)

Most of the rocks exposed in the San Marcos Mountains are ancient granites of late Mesozoic age (100 to about 70 million years) associated with the formation of an ancient volcanic arc associated with a regional subduction zone offshore. The massive granite peaks throughout the San Marcos Mountains are remnants of large granitic plutons (associated with a greater Peninsular Range Batholith). These plutons were no doubt associated with a chain of volcanoes that have long since eroded away (possibly rock mass miles thick have eroded away in the area since the end that volcanic era). These ancient igneous plutons intruded older ancient ocean crustal rocks of undetermined age. These ancient rocks include seafloor crustal rocks (basalts and sediments) that have been heavily altered by regional metamorphism.

The rocks on the high peaks of the San Marcos Mountains display an interesting history associated with climate history and weathering. The granite bedrock is deeply fractured and weathered by exposure to groundwater and air. Fire has also had a very significant role in the weathering of rocks. In many places the soil is deeply red or brown, and lacks organic remains after many generations of exposure to wildfire. Many of native plants are also adapted to wildfire and may even require it to reproduce. Heat from wildfire helps break down granite, and the mineral limonite (an orange iron hydroxide mineral that is basically rust) gets baked into red hematite (iron oxide).

Zoomed in view of Big Bear (mountains) from Double Peak.
Distant view of Big Bear in the San Bernardo Mountains as seen from Double Peak.
Scorched earth and burnt bushes on Double Peak after 2014 fire.
Fire-damaged landscape on Double Peak after massive wildfire in 2014.
Escondido Creek in Elfin Forest Recreational Reserve.
Escondido Creek flows through Elfin Forest Recreational Reserve
View from Lake Hodges Overlook in the Elfin Forest Recreational Reserve.
View from Lake Hodges Overlook in the Elfin Forest Recreational Reserve
Panoramic view of Olivenhain Reservoir.
Lake Olivenhain is a reservoir constructed high in the San Marcos Mountains, accessible by the upland trails in the Elfin Forest Preserve and from a trailhead on the Del Dios Highway (see map above).

Lake Hodges

Lake Hodges and surrounding reserve lands are part of the San Dieguito River Park system. The preserve around Lake Hodges provides interesting geology, archeology, and spectacular scenery of the highlands of the southern San Marcos Mountains. Many miles of trails surround the lake and follow the river course.

Lake Hodges - Kayaking and Hiking Info

I (the writer) spends a lot of time on Lake Hodges. The trail system is awesome for hiking or biking. Bring a walking stick because I frequently see rattlesnakes here (don't hurt them! They live here, you don't!). The walk along the West Shore Trail passes through a lot of shade, ideal for the summer. The trail passes Lake Hodges Dam and continues down Del Dios Gorge along the San Dieguito River. The other hiking trails around the Piedra Pintadas and North Shore areas are more open (exposed), and are better to hike in cool weather, especially during spring wild flower season. A hiking trail to the top of Bernardo Mountain provides spectacular views of the region. The North Shore Trail continues up the San Dieguito River Valley (San Pasqual Valley) as the Mule Hill Trail on the east side of Interstate 15 (see below).

Lake Hodges is ideal for a kayak (or a boat) field trip - bring you own, or rent one. Thefun destination is to kayak out to a wind vortex area created by a wind gap in a peninsula. It is an ideal location to study how wind influences wave and ripple patterns, how topography effects wind patterns, and how wildlife (particularly birds called Grebes) respond to wind patterns and upwelling.

Definitely plan to make a day of it if you can! Pack a lunch and bring lots to drink. This is a spectacular trip if you can pull it off. Lake Hodges is only open on Wednesdays and weekends, and is closed after Thanksgiving until early February when large numbers of birds winter on and around Lake Hodges.

A Del Dios Trailhead on the neaby Del Dios Highway joints trails in the Elfin Forest Recreational Reserve and leads up the the Lake Hodges Overlook area. About 3 miles west of the Lake Hodges Dam is a trailhead to access trails to the Del Dios Gorge area.
Map of Lake Hodges area and Elfin Forest Recreational Reserve.
Map of Lake Hodges and Lake Olivenhain in the San Marcos Mountains. This map shows the major trails throughout the area and the location of scenic overlooks on the trail system.

Western Diamondback Rattlesnake on road. Western diamondback rattlesnakes are generally docile and will move away if unprovoked. Mountain bikers and dog owners need to be especially aware.
Panoramic View of Lake Hodges from Lake Hodges Overlook in the Elfin Forest Recreational Reserve.
View of Lake Hodges from the Lake Hodges Overlook in the Elfin Forest Recreational Reserve.
View of Lake Hodges from the top of Bernardo Mountain.
View of Lake Hodges and San Marcos Mountains from the top of Bernardo Mountain Summit Trail.
Waterfall and granite along the Piedras Pintadas Trail on the south side Bernardo Bay on Lake Hodges.
Waterfall and granite along the Piedras Pintadas Trail on the south side Bernardo Bay on Lake Hodges.
View looking upstream at Lake Hodges Dam.
Lake Hodges Dam was first constructed in 1918 in the Del Dios Gorge along Escondido Creek.
Granite "rock garden" next to Escondido Creek along the lower Del Dios Gorge Trail downstream of the dam.
Granite "rock garden" next to Escondido Creek along the lower Del Dios Gorge Trail downstream of the dam.

San Pasqual Valley Destinations

The trail system around Lake Hodges continues upstream of I-15 as the Mule Hill Trail. Mule Hill is part of the San Pasqual Battlefield State Historic Park.The park honors the soldiers who fought in the battle between the U.S. and Californio forces on December 6, 1846 in the midst of the Mexican-American War. The San Diego Archeaological Center is located near the park and the San Diego Zoo Safari Park. The Mule Hill Trail is a flat, exposed trail at its western end and passes along agricultural fields The trail crosses the San Dieguito River before climbing through scenic granite terrain at its western end. Exhibits about the battlefield are presented near Mule Hill. The trail is hot in the summer and may be flood after winter storms. A bike ride on a cool morning in spring flower season is ideal.
Nearby Kit Carson Park is host to the Queen Califia's Magic Circle scupture garden (below).
Map of the San Pasqual Valley
Map of the San Pasqual Valley and Mule Hill Trail, Kit Carson Park, San Diego Archeaological Center, and San Diego Zoo Safari Park.
Panoramic view of Queen Califia's Magic Circle

Queen Califia's Magic Circle

Queen Califia's Magical Circle is the work of sculpture Niki de Saint Phalle (born France, 1930-2002). You can read about the history and inspiration of this amazing sculpture garden at a website: Niki de Saint Phalle's Queen Califia's Magical Circle. Her magic circle was inspired by California's mythic, historic and cultural roots. The sculpture garden consists of nine large-scale sculptures, a circular snake wall, and a maze entryway.

Why is this an excellent geology field trip? What is amazing is the abundance of different minerals and semiprecious gemstones used in the construction of this amazing piece of art! If you go there, bring a guide to common minerals and gemstones with you and make a list of all the materials used in its construction. It rivals geology museum collections anywhere! It is also a delightful place to visit, especially with children!

Queen Califia's Magical Circle is situated within a 12-acre natural habitat within the Iris Sankey Arboretum in Kit Carson Park. The park's entrance is located five minutes from I-15 (Via Rancho Parkway Exit) at the corner of Bear Valley Parkway and Mary Lane.
Look at the Park's website before you visit. Hours of access are limited. See the Lake Hodges Map above to see the location of Queen Califia's Magic Circle in Kit Carson Park on the Lake Hodges maps above.

San Diego Archaeological Center

The San Diego Archaeological Center is a repository to preserve archaeological collections The organization's goal is to promote their educational, scientific and cultural use to benefit a diverse public. The Center was established in 1998 to help resolve a "curation crisis" - collections of artifacts that were distributed between multiple organization and collects that might be considered illegal under Federal Law (Antiquities Act).

The center is located near the entrance to the Wild Animal Park on Highway 78 east of Escondido. The small center has an excellent array of collections on display including artifacts going back nearly 10,000 years up to the present age.

Prehistoric indian artifacts in a display case.
Example of a display collection in the San Diego Archaeological Center.


Map showing location of the San Diego Archaeological Center and the San Pasqual Battlefield near the San Diego Zoo Safari Park

San Diego High Country

The high peaks of east-central San Diego County are visible from many locations in San Diego County. There are many places to visit in the high country. The town of Julian is close to many of the high peaks. Popular destinations include Cuyamaca State Park, Volcan Mountain Wilderness Preserve, and William Heise County Park.
List of the High Peaks in San Diego County
High Peaks in
San Diego Co.

Map of the High Country in central-eastern San Diego Co.

Cuyamaca Mountain view from Volcan Mountain Trail

Palomar Mountain and Palomar Observatory & Museum

Mount Palomar is a high ridge of granite bedrock uplifted along a linear trend on the east site of the Elsinore Fault Zone (a major earthquake fault zone that runs north-to-south across central San Diego County. The high point of Palomar Mountain is 6,138 feet (1780 meters). Many pegmatite dikes are exposed in the road cuts in the granite bedrock along the road up to Palomar Mountain summit. Palomar Mountain State Park is host to many miles of hiking trails through upland forests. Mortar holes carve in granite outcrops reflect the ancient heritage of prehistoric native populations using this mountain.

The Palomar Observatory and Museum are essential destinations for regional fieldtrips! The Observatory ground are spectacular scenery with large redwoods and sequoia trees planted over 100 years ago. The Museum exhibits have been recently updated and describe many of the amazing aspects of what we now collectively know about the age, size, and features within the Observable Universe.
View looking east toward the San Marcos Mountains from Palomar Mountain overlook.
View looking west from Palomar Mountain toward the San Marcos Mountains. The Elsinore Fault (a major regional earthquake fault) runs north-to-south in the valley west of Palomar Mountain.
Map of Palomar Mountain and Observatory
Map showing location of Palomar Mountain and Palomar Observatory.
Palomar Mountain is about a 2 hour drive from anywhere in coastal San Diego, but it is well-worth-the-visit. Camping in Palomar Mountain State Park is highly recommended!
Granite pegmatite dike in road cut along Palomar Mountain Road.
Pegmatite dikes cutting through older granite plutons is common on Palomar Mt.
400 year old insence cedar on Palomar Mountain.
Palomar incense cedar (400 years old) are common in old forests on Palomar Mountain.
Mortar holes in granite outcrop on Palomar Mountain.
Ancient Indian mortar holes worn into granite outcrops are an important prehistory story.
Mount Palomar Observatory building.
Mt. Palomar Observatory and Museum are an important educational destination!

Anza Borrego State Park

Anza Borrego State Park is the largest state park in the United States! The park is an excellent fieldtrip destination, for a day or a week. There are so many places to see and go in the park. A visitor center in Borrego Springs is an excellent place to start. There are many places to camp and trails to hike. It is very important to check weather conditions before visiting, summer temperatures are frequently in the 100s. Spring wildflower season is perhaps the best time to go.
Anza Borrego State Park website
Anza Borrego State Park Map

Agua Caliente County Park - this county park has camping and hot spring-filled pools. The park is closed in summer.
Anza Borrego State Park location map.
Map of Anza Borrego State Park
Human for scale in front of cliff of stacked conglomerate beds.
Fanglomerate (alluvial fan deposits) exposed in Split Mountain (canyon).
An ocotillo plant and barrel cactus  in the Anza Borrego desert.
Ocotillo and barrel cactus
Agaves growing along a trail in Anza Borrego desert.Agaves and cactus
Overllok view of the Carrizo badlsnds.
Carrizo Badlands
Faulted-mountain front in Anza Borrego desert.
Faulted-mountain front
A rocky slot canyon narrow passage in Anza Borrego State Park.
Slot canyon in Anza Borrego

Santa Catalina Island

Santa Catalina is a spectacular field trip/camping destination for those who have time and means to get there. The island is a massive mountain of exposed ocean crust (a piece of the ancient Farrollon Plate). Stop at the Catalina Island Conservancy Nature Center during a hike up to the Wrigley Memorial & Botanical Garden, or better a hike up to the high ridgeline near the town of Avalon provides spectacular view. A shuttle runs between the two ferry ports in the towns of Avalon and Two Harbors. You can get there by taking the Catalina Express (ferry).

Map of Catalina Island

Sunset over Catalina Island.
Panorama view of the crest of Catalina Island from about a 3 mile hike up from downtown Avalon.
Panorama view of the crest of Catalina Island from about a 3 mile hike up from downtown Avalon.

Museum Destinations

San Diego Natural History Museum: Located in Balboa Park featuring exhibits, lectures, classes and field
trips related to natural history for all ages. The museum has xceptional regional fossil displays and an Imax theatre.

Plan to send a day in Balboa Park! The cactus and rose garden next to the Natural History Museum are spectacular! There are many of the other museums in the park. Bring a picnic, and plan to spend the day!
Be sure to walk through the Cactus Garden Trail next to the Rose Garden across the street from the Natural History Museum.

The San Diego Zoo is also in Balboa Park. The Zoo is not only a world-class zoo, it is also one of the best and most impressive botanical gardens in the world. The park has numerous exhibits and information resources, not only about life on the planet, but paleontology as well.
Balboa Park
Map of Balboa Park
Replica af a Stegasaurus dinosaur.
Stegasaurus replica.

San Diego Cretaceous-age ammonite fossils.



Tyranosaurus skeleton display.
Classic T-rex replica


Fossil mastadon skeleton.
Bones and remains of fossil mastodons and mammoths of the Pleistocene Epoch are not uncommon fossils from San Diego County.


Saber-tooth cat fossil.
Saber-tooth cat fossils from the late Pleistocene Epoch have been found in San Diego County. Their fossil remains have been retrieved in abundance from the La Brea Tar Pits in Los Angeles

Gemological Institute of America

If you live in the San Diego area, consider taking a guided tour at the Gemological Institute of America (GIA) in Carlsbad, CA. The GIA offers tours of their facilities where students and professionals are taught how to identify, evaluate, and work with gems and precious stones. The main building at GIA Headquarters has hallways lined with exhibits filled with exceptional examples of gems and provide discussions about their nature and occurrence. The GIA a large hall with special exhibits, and a room with one of the best mineral and gem-bearing rock exhibits in the world. The tour is free, but must be scheduled by reservation in advance. GIA is an excellent place to learn more about gems and minerals. Note that San Diego County has a long history of gem mining, and GIA provides a lot of information about historic mining operations with spectacular examples of local tourmaline, morganite, and other gem minerals.
Pink geode with radial crystals of rhodocrosite Aquamarine gemstones. Green emerald crystal in white matrix. Purple tourmaline crystals in white matrix in display case.

Sea World - This can be turned into an OK fieldtrip if participants examine all the displays about sea life and that examine the science behind Sea World. Although a commercial venture focused on entertainment, there are many science and environmental exhibits. Sea world is a good destination for students with children.

Finding Geologic and Geographic (Map) information for lands and resources in the United States

USGS National Geologic Map Database - This website (database) provides access to free digitized geologic maps, geologic information, information about stratigraphy, and other resources for map coverage of the United States.
USGS Topographic Maps (all scales) for the United States (via Topoview) - search this site to download topographic maps - you will have to "unzip" to view and/or save files before viewing or editing in software (such as ArcGIS, Photoshop, etc.)
Google Maps - the simplest and fastest way to access "revised" road maps, directions, and satellite views of the entire world.
Google Earth - Download this software to a computer and you can "virtually fly" to any location and get views of features along roads, rivers, etc. Google Earth allows you to upload geographic and geologic information as data layers imported as ".kml" files. Search on-line (using ".kml" as a keyword) to see if the type of information you are seeking exists for uploading data into Google Earth. (Example, in your web browser search keywords "earthquake faults California .kml".)
USGS Geographic Names Information System (GNIS) database contains information about "federally recognized" names of physical and cultural geographic features in the United States and associated areas, both current and historical (not including roads and highways).
The National Map (USGS) is another source of map information and access point to download and view geographic (map) information for topography, elevation, transportation, water (hydrography), political boundaries, land cover, and othoimagery (rectified aerial photography).
http://gotbooks.miracosta.edu/fieldtrips/index.html 6/23/2018