Canyon of Lodore, Green River. Dinosaur National Monument. Moffat County, Colorado. June 1871.
USGS Earth Science Photographic Archive digital file: hjk00503

Note about anaglyphic images: the red color is associated with the left image, the cyan color is associated with the right. In this case the "left" side of plate was broken, causing the cyan to stand out where part of the plate is missing (both images were typically burned onto a single plate negative in the camera equipped with dual lenses). When red and cyan are combined in the images, the result is a gray-scale palette (white to black). The aged original photographs also had brownish tones that come through in many of the images. Unusual shaped patches of red or cyan color are usually imperfections in the original negative plates, either scratches or where the coating may of rubbed off or were perfectly prepared before exposure. Considering the time constrains, methods involved, and circumstances required to take and transport the glass plates, cameras, and photographs supplies, the survival of so many scenes is a reflection of the remarkable dedication to the photographic aspects of the expedition.