I began at the Lake Mead National Recreation Area parking lot off Highway 93 (Great Basin Highway) -- turn onto Riverside Road and then right to the visitor center, and this lot also serves the Historic Railroad Bridge Trail. The parking area has several sign kiosks with interesting info for you. Bike a bit up the hill on the paved trail and you'll quickly see the gravel Railroad Tunnel Trail going off to the left. The paved trails heading each direction are the Loop Trail.
The trail is paved and 12 feet wide and for about 15 miles has an adjacent equestrian trail. Nearly four miles follow an old rail line used to supply materials to the Hoover Dam construction site. A parking area at the Lake Mead National Recreation Area visitor center serves both this trail and the Historic Railroad Bridge Trail. You can see Lake Mead in the distance in this photo...
Tunnels are used to avoid some street crossings...
...and in a few places, the trail is actually the flood water runoff channel and signs warn you to stay out during rain storms.
This trail is for the very hearty since it involves much elevation gain in some areas. To avoid the most strenuous uphill sections, you can bike the Historic Railroad Tunnel Trail and the segments of the Loop Trail that go each way from the visitor center parking area. You'll still get great views of the lake as well as a good workout!
You can access the trail in several places:
1) Railroad Pass Hotel Casino, 2800 S. Boulder Hwy., Henderson; upper parking lot
2) Bootleg Canyon Park, Yucca St. & Nevada Hwy., Boulder City
3) Lake Mead NRA Visitor Center, Lakeshore Rd. & Nevada hwy 4) Lake Mead NRA Fee Station, Lake Mead Parkway going east out of Henderson & Lakeshore Rd.
5) Equestrian Park, Foothills Drive & Equestrian Drive, Henderson