History of the Hoover Dam Railroad:

• 1931: Lewis Construction Company began construction under Bureau of Reclamation
• 1961: Last year railroad in use
• 1962: Tracks dismantled and sold for scrap to Lucia Brothers
• 1984: Nominated to National Register of Historic Places
• Length: 2.6 mi. from gate to the entrance of tunnel 5 
• One of two most difficult sections of track to construct, only remaining section of Hoover Dam Railroad system that is not highly disturbed or under water.
• All tunnels are approximately 300 ft. in length, and 25 ft in diameter. The tunnels were oversized to fit penstock sections and large equipment being transported to Hoover Dam.
• Nine steam and four gas locomotives and 71 people were used to operate the system. It was a standard-gauge, 90-pound rail construction that used Oregon fir ties.
• This section was used in the motion picture "The Gauntlet" starring Clint Eastwood and Sondra Locke for a sequence in which they were on a motorcycle being chased by an assassin in a helicopter.

The Hoover Dam construction railroad system had three segments. The first, from Las Vegas to the Boulder City site, was built and operated by the Union Pacific Railroad.

The second segment was built by the U.S. Government. It ran from Boulder City down Hemenway Wash to Himix, the concrete mixing plant on the rim of the Black Canyon overlooking the dam. It provided concrete for the final 242 feet of the dam and the buildings on its crest.

Six Companies, Inc. built and operated the third segment of the system. The tracks branched off about a mile up Hemenway Wash from the Visitor Center. It crossed Hemenway Wash and followed the base of the River Mountains and then looped eastward to the gravel plant on the flat overlooking the Colorado River. In 2009 the water elevation was low enough to see a gravel cleaning pool on one of the "Black Islands about 1/2 mile NE of Hemenway launch ramp. It looks like a cement water reservoir.

Isolation demanded the tons of concrete needed for the dam to be manufactured locally. An electric dragline with a five cubic yard capacity loaded gravel into railroad cars. Concrete was made by mixing sand and crushed rock, called aggregate, with portland cement and water. Over four million cubic yards of aggregate were taken from the Arizona side of the river.

The other branch followed the river downstream into Black Canyon, to Lomix, a concrete mixing plant situated at the base of Black Canyon. Lomix provided the concrete for the diversion-tunnel linings, the powerhouse foundation, and two-thirds of the dam. To prevent the concrete from drying during transportation the mixing plant was put as close to the river as possible.

Locomotives hauled tons of gravel to a screening plant on the other side of the river 24-hours a day. A round trip took slightly over two hours. The foundations of the plant are now about 150 feet below the water level of Lake Mead.

The Six Companies Railroad was abandoned after the completion of Hoover Dam in 1935. The U.S. Government Construction Railroad section was sporadically used until 1961, when the last generator was hauled over its rails and installed at the power plant.

The tracks were dismantled in 1962 and sold as scrap to Lucia Brothers. The tunnels and trail were nominated in 1984 to the National Register of Historic Places.

Today you can walk or bicycle along the elevated railroad bed used to haul supplies and materials for the construction of Hoover Dam. Enjoy the spectacular views of Lake Mead and the surrounding desert landscape.  The trail head for the railroad hike starts at a parking lot very close to the Alan Bible information center.  From this parking lot it's about 1mi to the first tunnel as you hike uphill and to the East.  The closest way to hike the trail is to drive to the Lake Mead viewpoint just off highway 93, 1.5mi East of Hacienda Hotel.  When you park at this viewpoint you're ON TOP of one of the tunnels. You can hike down the SE side of the viewpoint hill down to the tunnel that's right under the viewpoint. This is an easy hike down, not very steep, and it's short.  From this  tunnel under the viewpoint you can hike West toward the visitor center and see the other 4 tunnels. This "viewpoint hike" shortens your total hike about 2mi.