The Historic Railroad Hiking Trail is a 7.5-mile round-trip mile hike with views of the mountains and Lake Mead and five 300-foot-long and 25-foot-wide tunnels along the way. (Jayme Sileo/Boulder …

The Historic Railroad Hiking Trail is a 7.5-mile round-trip mile hike with views of the mountains and Lake Mead and five 300-foot-long and 25-foot-wide tunnels along the way. (Jayme Sileo/Boulder City Review)