Boulder Canyon, originally Devils Gate Canyon, is a canyon on the Colorado River, above Hoover Dam, now flooded by Lake Mead.
 It lies between Clark County, Nevada and Mohave County, Arizona.
 It heads at western end of the Virgin Basin of Lake Mead, at .
 The Canyon divides the Black Mountains into the Black Mountains of Arizona, and the Black Mountains of Nevada.
 Its mouth is under the eastern end of the Boulder Basin of Lake Mead, between Canyon Point in Nevada and Canyon Ridge in Arizona.
 Its original mouth is under Lake Mead between Beacon Rock and Fortification Ridge on the south shore in Arizona.
Lake Mead is the largest reservoir in the United States in terms of water capacity.
 Formed by the Hoover Dam, the reservoir serves water to the states of Arizona, California, and Nevada, providing sustenance to nearly 20 million people and large areas of farmland.
 Lake Mead is on the Colorado River, about 24 mi from the Las Vegas Strip, southeast of the city of Las Vegas, Nevada, in the states of Nevada and Arizona.
The Black Mountains, a mid-Miocene formation, in Nevada are a series of rugged, arid rocky volcanic mountains ranging in elevations to 3310 ft. The range lies on the north shore of Lake Mead, at the southwest corner of the Overton Arm, about 25 mi south of Overton, Nevada.
The San Luis Reservoir is an artificial lake on San Luis Creek in the eastern slopes of the Diablo Range of Merced County, California, approximately 12 mi west of Los Banos on State Route 152, which crosses Pacheco Pass and runs along its north shore.
 It is the fifth largest reservoir in California.
 The reservoir stores water taken from the San Joaquin-Sacramento River Delta.
 Water is pumped uphill into the reservoir from the O'Neill Forebay which is fed by the California Aqueduct and is released back into the forebay to continue downstream along the aqueduct as needed for farm irrigation and other uses.
 Depending on water levels, the reservoir is approximately nine miles long from north to south at its longest point, and five miles (8 km) wide.
 At the eastern end of the reservoir is the San Luis Dam, or the B.F. Sisk Dam, the fourth largest embankment dam in the United States, which allows for a total capacity of 2041000 acre.ft .
Fortification Hill is a prominence adjacent to Lake Mead in the Lake Mead National Recreation Area; it is located at the northwest terminus region of the Black Mountains (Arizona), and specifically the "north region" of the Black Mountains.
 It is near a southern section of Lake Mead, and just northeast of Hoover Dam.
 It can easily be seen eastward across Las Vegas Bay or from the two northern mountain terminuses of Eldorado Mountains (Nevada), or the Black Mountains (Arizona).
Las Vegas Bay is a bay at the western edge of Lake Mead in the U.S. state of Nevada.
 The bay is located within the Lake Mead National Recreation Area to the northeast of the city of Henderson, Nevada, near the junction of Lake Mead Drive and Lake Mead Boulevard.
 A public campground and boat access are available in Las Vegas Bay.
 Low water levels of Lake Mead have rendered the marina there inoperable, and it has moved to the Hemenway Boat Harbor, in the south end of the Boulder Basin.
 The launch ramp there has also been closed due to the water levels.
Lake Mohave is a reservoir on the Colorado River between the Hoover Dam and Davis Dam in Cottonwood Valley defining the border between Nevada and Arizona in the United States.
 This 67 mile stretch of the Colorado River flows past Boulder City, Nelson, Searchlight, Cottonwood Cove, Cal-Nev-Ari, and Laughlin to the west in Nevada and Willow Beach and Bullhead City to the east in Arizona.
 A maximum width of 4 miles wide and an elevation of 647 ft , Lake Mohave encompasses 28,260 acres of water.
 As Lake Mead lies to the north of the Hoover Dam, Lake Mohave and adjacent lands forming its shoreline are part of the Lake Mead National Recreation Area administered by the U.S. National Park Service.
Ah Pah Dam was a proposed dam on the Klamath River in the U.S. state of California proposed by the United States Bureau of Reclamation as part of its United Western Investigation study in 1951.
 It was to have been 813 ft high and was to be located 12 mi upstream of the river's mouth.
 It would stand almost as tall as the Transamerica Pyramid building in San Francisco, but would be much more massive.
 It would flood 40 mi of the Trinity River, including the Yurok, Karuk and Hupa Indian Reservations, the lower Salmon River, and 70 mi of the Klamath River, creating a reservoir with a volume of 15000000 acre.ft – two-thirds of the size of Lake Mead, and becoming the largest reservoir in California.
 The water would flow by gravity through a tunnel 60 mi long to the Sacramento River just above Redding and onward to Southern California, in an extreme diversion plan known as the Klamath Diversion.
 The tunnel would have been located near the southernmost extent of the reservoir.
 It was named in the language of the Yurok people.
Lake Powell is a reservoir on the Colorado River, straddling the border between Utah and Arizona (most of it, along with Rainbow Bridge, is in Utah).
 It is a major vacation spot that around two million people visit every year.
 It is the second largest man-made reservoir by maximum water capacity in the United States behind Lake Mead, storing 24,322,069 acre.ft of water when full.
 However, due to high water withdrawals for human and agricultural consumption, and because of subsequent droughts in the area, Lake Powell is currently larger than Lake Mead in terms of volume of water currently held, depth and surface area.
Boulder Wash is an ephemeral stream or wash in Clark County, Nevada.
 Its mouth is at its confluence with the Boulder Wash Cove of Lake Mead at an elevation 1,276 feet / 389 meters at when Lake Mead is at its full level.
 Currently as the reservoir is at a much lower level its mouth is found at approximately .
 Its source is at at an elevation of 2,841 feet / 866 meters in the Black Mountains.
 It flows down a canyon into the upper Pinto Valley southwestward before turning southeastward to Boulder Wash Cove.

Question: The Black Mountains, a mid-Miocene formation, in which U.S. State, are a series of rugged, arid rocky volcanic mountains ranging in elevations to 3310 ft, the range lies on the north shore of Lake Mead, the largest reservoir in the United States in terms of water capacity?
Answer: Nevada