Lost Lake (also known as Lost Lake Resort and Lost Lake Landing) is a desert community located along the west shore of the Colorado River. It also lies along U.S. Route 95 near the northeast extent of Riverside County. Official U.S. Geological Survey feature ID is 245216 and NAD27 coordinates for the community are (34°00′44″N114°28′27″W). The community lies at the foot of Riverside Mountain, (34°00′49″N114°30′45″W). with a summit measuring 2,127 feet.