Nicknamed "Furnace Flats," this exceptionally exposed, rocky and unmaintained 9-mile wilderness trail is infamous for being one of the hottest and most difficult rim-to-river hikes on the South Rim. In the winter, clap-ons are a must and in the summer bring plenty of water. There are no water sources until the Colorado River, where silt makes purification difficult.

A natural route roughly along the current path was used by the canyon's Ancestral Puebloans for thousands of years, and today's trail remains relatively unchanged from that used by Grand Canyon miners in the late 19th-century. This trail is for experts only. Do not attempt to hike it without first securing a detailed map and talking to park rangers, and do not hike alone. At-large primitive camping is allowed with advanced backcountry permit.