abandoned activity adventure alleghany bad black hills civil defense collapse dangerous delamar eldorado exploring game gear ghost town gold mine gri grigri guessing hill jacob city keystone lbcc little brush locations lucky friday meeting mine miner mines mine tour nelson nevada nv. ohpir open mine ophir original sixteen to one owl park city performance petzl pics poor preservation problems projects public rails recall restoration saftey searchlight slow srt timbering tonight trapped tunnel underground gold miner utah utah queen