Roughly 50 miles east of Hanksville, in the rough country around the Dirty Devil River in southeastern Utah, a maze of slot canyons gave Butch Cassidy and the Wild Bunch a hideout that lawmen could not find. This episode treats Robbers Roost as its main character: a natural funnel of sandstone where a posse had to ride single file and one man with a Winchester on the high ground could hold off an army. Cassidy and his closest friend, Elzy Lay, forged the gang here and returned after major robberies to lie low for a month or longer.

The surprise is how domestic the place was. The outlaws built cabins to survive Utah winters, kept horses, cattle, and flocks of chickens, and played poker with $20 gold pieces while the Pinkertons searched in vain. Their lifeline was a supply chain run with the help of sympathetic ranchers Ann and Josie Bassett, who moved beef and horses over bare slickrock and up shallow riverbeds so that no tracks survived. The story then turns to the raid that finally breached the canyon and to the hikers and canyoneers who now seek out the same terrain for sport.

• A slot canyon can be hundreds of feet deep yet only a few feet wide at the bottom, which made numbers meaningless for any posse that tried to enter.
• Livestock was driven across solid sandstone and through the Dirty Devil’s shallows, where hooves left no mark and running water erased the rest.
• Only five women are known to have been allowed inside: Ann and Josie Bassett, Etta Place, Elzy Lay’s girlfriend, and Laura Bullion, a gang member in her own right.
• According to cowboy detective Charlie Siringo, a posse of Salt Lake City officers led by Joe Bush used informants and a narrow pathway to raid the Roost, killing several gang members.
• The hideout lives on in Robert Redford’s book The Outlaw Trail, a Zane Grey novel named for it, and canyon shootouts in Red Dead Redemption 2.