AtlasWaterpocket Fold

Muley Twist Canyon

verified Ungraded Unknown flood risk
Muley Twist Canyon
Alan Schmierer, CC0, via Wikimedia Commons

Not a slot in the technical sense: 16.5 miles of deep, meandering wash cut clean through the Waterpocket Fold, walkable end to end with no rope. Rated 1A, and the park lists it as either a long day or an overnight depending on which trailhead you start from.

Timing is the real decision. Four hours is the fast end and twelve the slow end, so pick your entry with the shuttle in mind rather than assuming a casual afternoon. No canyoneering permit applies because there is no rope work, but camping needs the free backcountry permit from the Capitol Reef visitor center, collected in person. Spring, fall, and winter are the listed windows; the fold bakes in summer. RopeWiki calls a passenger car adequate, which is true of the graded dirt on the Notom Bullfrog Road and the Burr Trail switchbacks in dry conditions and not true after rain.

Logistics

ManagerNPS Capitol Reef National Park
PermitNo canyoneering permit required since this route involves no rope work. Free backcountry permit required for overnight camping.
Distance16.5 mi
Technicallongest 0 ft
SeasonSpring;Fall;Winter
Vehicle accessPassenger
Coordinates37.8683, -111.0409

Sources