Historic Railroad Tunnel Trail

Historic Railroad Tunnel Trail

The August 3 challenge -- which 71 people got right -- was the Historic Railroad Tunnel Trail at the Lake Mead National Recreation Area near Boulder City, Nev., and Hoover Dam.

August 13, 2012 7:00 AM PDT

Photo by: Daniel Terdiman/CNET

 

Member Comments

Add Your Comment

Conversation powered by Livefyre