Risks to the Glen Canyon Dam that the resulting flood would scour the bottom few hundred feet of the Grand Canyon, overtop Hoover Dam, and cause severe damage all along the lower Colorado River. In the event of a complete dam failure with Lake Powell at high pool, about of water would surge out of Lake Powell at an initial depth of over . Downstream communities and perhaps every dam along the river, excluding possibly Hoover Dam, as well as riverside lowlands, would be inundated or severely damaged. Located downstream from Glen Canyon Dam are Hoover Dam forming Lake Mead, Davis Dam forming Lake Mohave, Parker
Steamboats of the Colorado River west side of the river sixty five miles above Fort Mohave near what was then considered the high water limit of navigation. George A. Johnson came up river and made a deal to supply the mines with his steamboats at $100 a ton, a lower price than the $240 a ton charged for overland freight across the Mojave Desert from Los Angeles. That fall news of the strikes brought a flood of miners to the canyon. Several camps were founded in the canyon. San Juan, or Upper Camp were at the top of the canyon, near modern Nelson, Nevada. Midway