Bluejohn Canyon is a remote slot canyon in eastern Utah on Bureau of Land Management land south of the Horseshoe Canyon Unit of Canyonlands National Park, outside the park boundary and about 42 miles south of Green River. Its main fork runs about 11 miles north-northeast from the Robbers Roost Flats before joining Horseshoe Canyon, with several smaller side canyons branching off. The full route demands technical canyoneering skills and equipment. The canyon’s name is probably tied to outlaw John Griffith, nicknamed Blue John. It became internationally known in 2003 when Aron Ralston escaped after five days trapped by a boulder by amputating his right forearm.