The Eldorado Mountains, also called the El Dorado Mountains, are a north-south trending mountain range in southeast Nevada bordering west of the south-flowing Colorado River; the endorheicEldorado Valley borders the range to the west, and the range is also on the western border of the Colorado River's Black Canyon of the Colorado, and El Dorado Canyon on the river. The range is southeast of Las Vegas, Nevada; and the Eldorado Mountains connect with the Highland and Newberry mountains.