Boulder Canyon (Colorado River) Boulder Canyon (Colorado River) Boulder Canyon, originally Devils Gate Canyon, is a canyon on the Colorado River, above Hoover Dam, now flooded by Lake Mead. It lies between Clark County, Nevada and Mohave County, Arizona. It heads at western end of the Virgin River Basin of Lake Mead, at about . Boulder Canyon divides the Black Mountains into the Black Mountains of Arizona, and the Black Mountains of Nevada. Its mouth is now under the eastern end of the Boulder Basin of Lake Mead, between Canyon Point in Nevada and Canyon Ridge in Arizona. Its original mouth is now underneath
The Exploration of the Colorado River and Its Canyons The Exploration of the Colorado River and Its Canyons The Exploration of the Colorado River and Its Canyons by John Wesley Powell is a classic of American exploration literature. It is about the Powell Geographic Expedition of 1869 which was the first trip down the Colorado River by boat, including the first trip through the Grand Canyon. Powell's first written accounts of his exploration appeared in the January, February and March 1875 editions of "Scribner’s Monthly" as "The Canons of the Colorado". The Smithsonian published it in book form in 1875 under title "Report of the Exploration of the Colorado