where was the material that was eroded by the colorado river deposited
Geology of the Grand Canyon area Uplift of the region started about 75 million years ago during the Laramide orogeny; a mountain-building event that is largely responsible for creating the Rocky Mountains to the east. In total, the Colorado Plateau was uplifted an estimated 2 miles (3.2 km). The adjacent Basin and Range Province to the west started to form about 18 million years ago as the result of crustal stretching. A drainage system that flowed through what is today the eastern Grand Canyon emptied into the now lower Basin and Range province. Opening of the Gulf of California around 6 million years ago enabled a large river to cut its way northeast from the gulf. The new river captured the older drainage to form the ancestral Colorado River, which in turn started to form the Grand Canyon.
Gold mining in Colorado On June 22, 1850, a wagon train bound for California crossed the South Platte River just north of the confluence with Clear Creek, and followed Clear Creek west for six miles. Lewis Ralston dipped his gold pan in a stream flowing into Clear Creek, and found almost $5 in gold (about a quarter of a troy ounce) in his first pan. John Lowery Brown, who kept a diary of the party's journey from Georgia to California, wrote on that day: "Lay bye. Gold found." In a notation above the entry, he wrote, "We called this Ralston's Creek because a man of that name found gold here." Ralston continued on to California, but returned to 'Ralston's Creek' with the Green Russell party eight years later. Members of this party founded Auraria (later absorbed into Denver City) in 1858 and touched off the gold rush to the Rockies. The confluence of Clear Creek and Ralston Creek, the site of Colorado's first gold discovery is now in Arvada, Colorado.[2]:6â€“7