Just 30 miles from Las Vegas, near Boulder City, the gravel Historic Railroad Tunnel Trail hugs the hills on the southern shoreline of vast Lake Mead. The rail-trail offers panoramic views of the manmade lake and snakes through five railroad tunnels on its way toward Hoover Dam.
After the dam was completed in 1935, the railroad ceased operation, and in 1962 the tracks were removed; the trail opened in 1995. Though it begins obscurely at Highway 93 and Pacifica Way in Boulder City, the best place to begin your trek is the Lake Mead National Recreation Area Visitor Center trailhead. This is also a shared trailhead for the River Mountains Loop Trail. Heading northward, you'll experience 3.6 miles of desert terrain trail through the Hemenway valley, where jackrabbits bound over washed-out gullies, bighorn sheep graze and the usual desert-dwelling snakes and lizards are at home.
On the easy, wide path you first pass through a high cut in the red, iron-rich volcanic rock. The cut was blasted out in 1930 for trains to pass through, carrying stone to the dam site. As the trail curves toward the edge of Lake Mead, you'll find yourself several hundred feet above the grey blue water. While the descent isn't a sheer drop, take care as there is no guardrail. The lake views are spectacular all along the trail. Peaks of ancient volcanic mounds rise above the lake surface of this drowned valley like the humps of an aquatic beast. Far in the distance the craggy, smoky blue South Virgin Mountains rise into the clouds.
Each of the five tunnels along the trail is 25 feet in diameter to accommodate the large equipment that passed through. In this unforgiving terrain, it's impressive to consider the sheer magnitude of force needed to blast the path. Pioneer trails from early dam construction parallel the trail intermittently.
Just before tunnel 1, look down the ravine to the right to see concrete plugs taken from Hoover Dam to install turbines. You come across the first and second tunnels in quick succession, and their dark interiors provide a cool respite from the desert sun. (The Lake Mead National Recreation Area discourages hikers on any of its trails in the summer months, but fall and winter are prime touring seasons.) As you pass through tunnel 2, notice that the ceiling and sidewalls have been reinforced. This work was done after the tunnel was burned by arson in 1990. Wildfire gives rise to much of the plant life along the trail; creosote and mesquite bushes, which are fire-resistant, are scattered in green and brown bundles along the trail and on the surrounding hillsides.
In tunnel 3 the arches were shored up to support the massive weight above. Fault lines are visible in the rippled texture of the sienna hillsides all along the trail, and particularly in the rock face about 20 feet before tunnel 4. Passing through tunnel 5, which was burned in 1978 and only reopened in 2001, you come to an opening in a fence where the trail continues. Follow the trail as it snakes through some steep hillsides and through industrial areas before reaching the endpoint in dramatic fashion; the trail brings you out on the top level of the visitor parking area, giving you an awe-inspiring view of the dam below.
To reach the Hoover Dam Visitor Center, simply take the elevator down to the first level and follow the signs.
To reach the Lake Mead Visitor Center trailhead, from Las Vegas take I-215 to I-515 South. Follow I-515 South for 5.8 miles to Highway 93 toward Boulder City. After 9.6 miles take a left onto State Route 166. Look for the Lake Mead Visitor Center sign. The trailhead is just over 0.3 mile ahead on the right.
To park at Hoover Dam, from Boulder City take US 93 for about 5 miles to the turnoff to Nevada Route 172/Hoover Dam Access Road. Follow it for about 2 miles to the dam.