Course of the Colorado River Davis Dam in Pyramid Canyon above Laughlin, Nevada, where a bridge carries NV 163 (Laughlin Highway)/AZ 95 over the Colorado River. Prior to the completion of the Hoover Dam Bypass project in 2010, this bridge was the main crossing for freight traffic between Arizona and Nevada as trucks were not allowed over Hoover Dam for security reasons after the September 11, 2001 attacks. The Colorado then passes by Bullhead City, Arizona and Fort Mohave, Arizona and the Fort Mojave Reservation. The Colorado forms the border of California to the west and Arizona to the east for most of its course
Risks to the Glen Canyon Dam annually at Glen Canyon, and as Lake Powell is the farthest large reservoir upstream on the Colorado River mainstem, the sediment load is completely trapped in the reservoir as the Colorado discharges into it. This sediment is creating a steadily advancing "toe" of sediment, i.e. an underwater alluvial fan, that is advancing towards the dam. It is estimated that the sediment will reach the dam base in a minimum as low as eighty to one hundred years or as far as 500 to 700 years, although it will take much more time for the sediment deposited there to reach higher