Bad Pass Trail, Archaeological trail in Big Horn County, United States.

Bad Pass Trail is an archaeological path running along the western edge of Bighorn Canyon, marked by stone cairns and tipi ring structures. The route extends from Shoshone River to Grapevine Creek and shows the physical traces of camps and travel routes.

The Bad Pass Trail, also called the Sioux Trail, was established by Native Americans in pre-Columbian times to reach bison-hunting grounds at Grapevine Creek from the Bighorn Basin. From 1824 fur trappers and mountain men used it to avoid Bighorn Canyon, assembling pack trains at the Shoshone-Bighorn junction and floating rafts down to St. Louis. It was listed on the National Register of Historic Places on October 29, 1975.

The trail displays tipi ring structures on both sides that reveal how Indigenous communities used this landscape across generations. These remains show where people made camp and lived during their journeys through the region.

The trail is accessible on foot but requires sturdy footwear due to rocky ground and uneven surfaces throughout. Visitors should bring plenty of water and avoid the area in heavy cloud cover, as navigation becomes difficult.

About three hundred cairns are known along the trail, most of them inside Bighorn Canyon National Recreation Area. The piles grew stone by stone, each passer-by adding one as a good-luck offering. Much of the route itself has since been erased by an access road built for area ranches.