A last few standing A-frames for the monorail of the old Wingate Pass Epsom Salt Mine. It is now part of the Death Valley National Park. A short outline of the history of the mine can be found here: http://www.frontiertrails.com/oldwest/esmpictures.htm . An overhead view of this area is here: http://terraserver.homeadvisor.msn.com/image.aspx?t=1&s=10&x=2529&y=19772&z=11&w=2