The Colorado River Basin provides habitat for 14 native fish,
including four endangered species protected under the Federal
Endangered Species Act of 1973 - Colorado pikeminnow (Ptychocheilus
lucius), razorback sucker (Xyrauchen texanus), bonytail (Gila
elegans), and humpback chub (Gila cypha). These endangered fish
species once thrived in the Colorado River system, but water-resource
development, including the building of numerous diversion dams and
several large reservoirs, and the introduction of nonnative fish,
resulted in large reductions in the numbers and range of the four
species. Knowledge of sediment dynamics in river reaches important to
specifc life-stages of the endangered fishes is critical to
understanding the effects of flow regimes on endangered fish habitats.
The U.S. Geological Survey, in cooperation with the Upper Colorado
River Endangered Fish Recovery Program, Bureau of Reclamation, U.S.
Fish and Wildlife Service, and Wyoming State Engineer's Office,
implemented daily sediment sampling at three locations in critical
habitat reaches in the Upper Colorado River Basin. This report
presents a summary of data collected at these sites, including water
and suspended-sediment discharge, streambed compositions, and channel
and flood-plain topography. The locations are at U.S. Geological
Survey streamflow-gaging stations 09152500, Gunnison River near Grand
Junction, Colorado; 09261000, Green River near Jensen, Utah; and
09302000, Duchesne River near Randlett, Utah.
