Frenchman Mountain is the highest peak in the craggy mountain range that forms the eastern border of the Las Vegas Valley. The range is composed of two peaks: Sunrise Mountain to the north and Frenchman Mountain to the south, which are separated by Lake Mead Blvd. From the perspective of town, Frenchman Mountain has two peaks: a northern lower summit (3,942 ft, actually twin peaks) and a southern true summit (4,052 ft, also twin peaks). Frenchman Mountain is located east of Las Vegas in the U.S. state of Nevada. Made up of rocks similar to those found on the bottom of the Grand Canyon, Frenchman Mountain formed when faulting elevated and tilted the rocks followed by erosion, giving it its sharp triangular profile. It is the site of the Great Unconformity with the tilted Paleozoic strata underlain by Paleoproterozoic Vishnu Schist, which is some of the oldest rock on the North American continent, having been created about two billion years ago.