Sauna Cave

Steamy man-made hot-spring tunnel just below Hoover Dam

InsideLake Mead National Recreation Area

Overview

Sauna Cave is a short, man‑made tunnel from the Hoover Dam era that intersects a hot spring, turning the passage into a steamy, geothermal nook. It sits less than a mile below the dam in Black Canyon, essentially right on the Colorado River—an odd, memorable side stop more than a destination soak.

What It’s Like Inside

Expect a narrow, dark corridor with shallow hot water underfoot and air that can feel well over 120°F. It fogs glasses and camera lenses fast. The footing is slick, the ceiling low in spots, and it turns pitch black within a few steps—plan a quick look rather than lingering.

Getting There

Most visitors reach it by water on the Black Canyon National Water Trail. Authorized outfitters launch just below Hoover Dam (permit and photo ID checks apply), then paddle downstream and pull in for a short walk to the entrance. You can also paddle upriver from Willow Beach, but that’s a strenuous full‑day effort against current and wind. If you’re attempting it by land, hikers typically use the Goldstrike Canyon route from the trailhead off I‑11, then scramble to the river; reaching the cave still works best from the shoreline.

Seasonal Closures & Safety

Goldstrike and nearby canyon routes close annually from May 15 to September 30 due to extreme heat. On the river, PFDs are required, the Colorado stays cold year‑round, and water levels can jump with dam releases—pull kayaks well above the line. Natural hot‑spring waters can harbor Naegleria fowleri; avoid getting water up your nose. Monsoon‑season storms can send flash floods through side canyons. Sundays and Mondays are motor‑free days in Black Canyon for a quieter paddle.

Nature to Watch For

Keep an eye on the cliffs for desert bighorn sheep. Great blue herons are common, and bald eagles winter in the area. Enjoy the view from the cave mouth—classic framing over the emerald river.

Best Time to Visit

October through March offers the most comfortable conditions for paddling and brief hot‑spring stops. Go early in the day for cooler temps and calmer winds. If attempting by land, plan outside the May 15–September 30 closure window and check park alerts before you commit.

Pros

Man-made tunnel tapped by a hot spring for a natural steam-room feel
Easy stop for paddlers on the Hoover Dam–to–Willow Beach run

Cons

No amenities; dark, slick, and narrow—bring a real headlamp
Best accessed from the river; land routes face seasonal closures (May 15–Sept 30)

Tips

Bring a headlamp—the cave goes pitch black almost immediately.
Treat it as a quick in‑and‑out stop, not a soaking spot.
If launching below Hoover Dam, book with an authorized outfitter early and bring photo ID.
Pull boats well above the waterline; dam releases can raise the river quickly.
Check park alerts and the May 15–Sept 30 seasonal closures before any canyon hike.