South Mountain Park — Hidden Valley and Fat Man’s Pass

Squeeze through a natural rock slot, slip under a stone tunnel and discover a pocket canyon hidden inside Phoenix.

The climb from Mormon Trailhead starts steeply before the route crosses to the National Trail and dips into Hidden Valley. Boulders, tight passages and weathered rock turn an urban hike into a playful scramble. Climb Mormon Trail, connect to National Trail, complete the Hidden Valley segment past Fat Man’s Pass and the natural tunnel, then loop back to Mormon Trailhead.

THE EXPERIENCE

Climb Mormon Trail, connect to National Trail, complete the Hidden Valley segment past Fat Man’s Pass and the natural tunnel, then loop back to Mormon Trailhead. The climb from Mormon Trailhead starts steeply before the route crosses to the National Trail and dips into Hidden Valley. Boulders, tight passages and weathered rock turn an urban hike into a playful scramble. The reward is not just the destination: it is the changing scenery, the effort of moving through it, and the satisfaction of completing a real outdoor route.

WHAT MAKES THIS PLACE SPECIAL

South Mountain’s extensive trail network preserves a rugged mountain landscape within the city; the rock features are natural weathering formations, not constructed attractions. Look for the natural rock slide and the tunnel-like exit from the wash, two memorable features on the same loop. This is a destination with a distinct personality rather than a generic viewpoint stop.

ROUTE AND TERRAIN

Plan for approximately 4 miles on a loop via mormon and national trails route, with a working elevation-gain estimate of 900 feet where applicable. The climb from Mormon Trailhead starts steeply before the route crosses to the National Trail and dips into Hidden Valley. Boulders, tight passages and weathered rock turn an urban hike into a playful scramble. Choose a pace that matches the terrain and your party abilities; actual mileage may vary with route choices.

ONCE YOU’RE THERE

Start at the official Mormon Trailhead at 8610 S 24th Street. Follow signed Mormon, National and Hidden Valley connections; the short Hidden Valley segment is only part of the full outing. Follow official posted signs and the current route map rather than improvised shortcuts.

FIELD GUIDE — WHAT TO NOTICE

Look for the natural rock slide and the tunnel-like exit from the wash, two memorable features on the same loop. South Mountain’s extensive trail network preserves a rugged mountain landscape within the city; the rock features are natural weathering formations, not constructed attractions. Look for the small transitions in terrain, vegetation and light that are easy to miss when focused only on the finish.

SAFETY AND PREPARATION

Expect exposed rock, uneven footing, heat and crowded weekends. The squeeze is optional for those uncomfortable in tight spaces; avoid slick rock after rain. Carry appropriate water, sun protection, offline navigation and a backup plan; conditions can change quickly.

FEES AND ACCESS

No mandatory entrance fee is identified for the specific public route described; verify any optional services or permits before travel.

BEST TIME TO GO

October through April; early morning outside cool season. Start early when temperatures or storms are a concern, and check current closures and access conditions.