Canyon of Desolation, Green River. Utah. (Negative broken).
USGS Earth Science Photographic Archive digital files: hjk00714 and hjk0714a

Note the barren floodplain along the river in this image. At the time of the Powell Survey expeditions scattered patches willows, cottonwoods and scrub oak grew on flood plains and intermittent terraces along the river. Today most of the floodplain areas like this are choked with tamarisk (salt cedar) that invaded the Colorado River basin in the early 20th Century.