Hole-in-the-Wall, Mountain pass in Johnson County, Wyoming, US.

Hole-in-the-Wall is a narrow gap in a long, layered wall of reddish-brown rock in the Big Horn Mountains of Johnson County, Wyoming. The opening cuts low through the ridge, with vertical faces and eroded ledges on either side. Below the pass lie pale tan and green ground, scattered trees and brush, a dirt road and fields.

From the late 1860s until around 1910, the pass served as a secure hideout for several outlaw groups. Butch Cassidy and the Wild Bunch used the hard-to-reach terrain for their operations.

The name comes from the narrow gap in the rock wall, the only way through. The cabin where Butch Cassidy, the Sundance Kid and others met was built in 1883 by Alexandre de Gand; it now stands at the Old Trail Town museum in Cody. At its height the site had several cabins, a stable, a corral, cattle and supplies, each gang helping with upkeep.

The pass lies in a remote, isolated stretch of the Big Horn Mountains, and the sources give no marked trail or fixed route to it. Approach is over rough mountain ground, so plan for changing Wyoming weather and carry your own supplies. The cabin associated with the gangs is not here: it was moved to the Old Trail Town museum in Cody.

The cabin where Butch Cassidy, the Sundance Kid and other outlaws met was built in 1883 by Alexandre de Gand. It was later moved to the Old Trail Town museum in Cody, so the pass itself keeps no building, only the narrow gap in the rock wall.