California BLM -
Staying on designated routes in remote public land areas of the California
Desert became an important lesson for an OHV recreationist and his
passenger who fell down a vertical mineshaft last weekend in eastern Imperial
County (luckily, a broken arm was the only injury). Traveling off-road in a
designated "limited use" area (where travel is restricted to identified safe
routes), the two men spent Sunday afternoon and night -- 20 hours total --down
the abandoned mineshaft before being rescued.
BLM arranged to have the vehicle extracted. An investigation is underway.
http://www.blm.gov/ca/news/newsbytes/xtra-06/222-xtra_minesafety.htm