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Colorado River Basin Maps
Figure 1. Map of the Colorado River Basin Showing Upper and Lower Basin Regions
Figure 1 is a map of the Colorado River Basin in the southwestern United States and northern Mexico, showing the legal division between the Upper Basin and Lower Basin at Lees Ferry, Arizona. The Upper Basin, shaded in light green, covers parts of Wyoming, Colorado, Utah, and New Mexico and includes the Green, Yampa, Colorado, and San Juan Rivers. The Lower Basin, shaded in darker green, covers parts of Arizona, Nevada, California, and Mexico and includes the Grand Canyon reach of the Colorado River, the Gila, Salt, Santa Cruz, and San Pedro Rivers, and the All‑American Canal. Major cities such as Denver, Salt Lake City, Las Vegas, Phoenix, Tucson, Los Angeles, San Diego, and Yuma, as well as Hoover Dam and Glen Canyon Dam, are labeled to provide geographic and infrastructure context.
Figure 2. Colorado River Basin and Adjacent Areas Served by Colorado River Water
This is a color map from the U.S. Bureau of Reclamation titled “Colorado River Basin and Adjacent Areas Served by Colorado River Water” showing the Colorado River Basin in the southwestern United States and northern Mexico, along with surrounding areas that receive Colorado River water. Land areas are shaded to distinguish the hydrologic basin from adjacent service areas, and state boundaries are outlined, including Arizona, California, Colorado, Nevada, New Mexico, Utah, Wyoming, and a portion of Mexico. A blue line marks the main stem of the Colorado River running from the Rocky Mountains through the Upper and Lower Basin states to the Gulf of California, with major reservoirs and water projects indicated along the river. The map includes labels for the Upper and Lower Colorado River Basin, key diversion projects, and some major cities or regions served by Colorado River water, and it uses a legend, scale bar, and north arrow to explain colors and symbols. The overall purpose of the map is to depict where Colorado River water originates and the broader region where that water is delivered.