El Dorado Canyon in southern Clark County, Nevada, became one of the region’s important early mining districts after gold and silver discoveries were underway by 1857. Draining east to the Colorado River at Nelson’s Landing, it developed camps along its length, including San Juan, Alturas, Louisville, and Colorado City, while the Techatticup Mine became a central site. During the Civil War years, local settlements reflected national political divisions, and in late 1863 a ten-stamp mill enabled ore to be processed locally, reducing costs and reshaping river trade. The district stayed active for decades, with mining continuing through periods of revival until World War Two.