The southern end of the extensive McCullough Range converges with four valleys and three mountain ranges at a water divide point. West of the McCullough's lie the endorheic Roach and Ivanpah Dry Lakes of Ivanpah Valley; the valley extends north into Las Vegas' southwest, a tributary to the Las Vegas Wash. Ivanpah Valley turns southeast to meet the water divide point. Northeast of the water divide point is the southwest Eldorado Valley, also endorheic with its Eldorado Dry Lake. Southwest, the Piute Valley drains south, then Piute Wash turns east and descends steeply at the Dead Mountains to its outfall at the Colorado River and Needles.