Frenchman Mountain is a mountain located east of
Las Vegas, 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. The mountain provides an example of the
Great Unconformity with the tilted
PaleozoicTapeats Sandstone[3] underlain by
PaleoproterozoicVishnu Schist, which is some of the oldest rock on the North American continent, having been created about two billion years ago.
The peak lies on a north to north-northeast trending ridge about 2000 feet above the nearby valleys.
Sunrise Mountain lies 3.6 miles (5.8 km) to the northeast adjacent to
Nellis Air Force Base. The north end of the
McCullough Range about 12 miles (19 km) to the south has a parallel trend. The
River Mountains lie to the southeast.[4][5]State Route 147 crosses its northern slope. A geologically rich area called Rainbow Gardens is located to its southeast, as is an igneous
laccolith, Lava Butte.[6]
The Frenchman Mountain Fault poses a significant
earthquake danger to the Clark County region.[7]
It is likely named after the Frenchman Mine, which itself was alleged to be the site of a stock scam by a Belgian immigrant (mistakenly assumed to be French).[8] It is commonly referred to as Sunrise Mountain, the name of a smaller peak to the north of Frenchman Mountain, because the sun rises over it in some areas of Las Vegas. The area from
Cheyenne Avenue and
Boulder Highway and
Lamb Boulevard is commonly known as
Sunrise Manor Township
CDP.
Local conservationists have proposed the area, along with
Gypsum Cave and Sunrise Mountain, be protected as a
national monument.[9]