Lost Man Hot Spring
By the HotSpringsFind editorial team · How we compile records · Reviewed September 2026
Wild thermal seep in Lost Man Canyon on the Arizona side of Lake Mead NRA just below Hoover Dam — a real hot spring but only a small stream of hot water with NO soakable pool; reached by kayak/boat on the Colorado River or by a hard Class-3 off-trail canyon scramble from the Kingman Wash parking area, and NPS bans damming the flow to build pools.
Field notes — checked May 2026
- Hazard: Extreme desert heat — summer land approach can be lethal (reason for the seasonal trail closure)
- Hazard: Unmarked Class 3 route with dryfalls; at least one pour-off may need a rope
- Hazard: Flash-flood risk in canyon narrows
- Hazard: Naegleria fowleri risk in warm thermal water — keep head above water
- Hazard: Remote — no services, no reliable cell signal
- NOTE: id prefix is wrong — this spring is in ARIZONA (Mohave County), not California
- No soakable pool — trip reports describe a small stream of hot water only; 'definitely a hot spring, but not the kind you'd want to soak in' (Stav is Lost, 2017/2020)
- NPS prohibits blocking/damming spring flow with sandbags to create pools
- Lake Mead's strenuous canyon trails (Arizona Hot Springs, Gold Strike, White Rock and related routes) close seasonally May 15-Sep 30 for extreme heat — in effect as of today; the springs themselves remain open to boaters year-round
- Land approach is NOT a maintained trail — unmarked route through Lost Man Canyon with Class 2/3 scrambling and dryfalls; one dead-end required a rope
- Naegleria fowleri (brain-eating amoeba) advisory for Lake Mead hot springs — do not submerge your head or splash water up your nose
- Kingman Wash Road is ~3.5 mi of dirt off US-93 to the parking area; most visitors come by boat/kayak up the Colorado from Willow Beach
- Lake Mead NRA entrance fee applies to park entry points
Current status
Wild thermal seep in Lost Man Canyon on the Arizona side of Lake Mead NRA just below Hoover Dam — a real hot spring but only a small stream of hot water with NO soakable pool; reached by kayak/boat on the Colorado River or by a hard Class-3 off-trail canyon scramble from the Kingman Wash parking area, and NPS bans damming the flow to build pools.
Checked May 2026 · verified against an official source · 4 sources ↓
About this spring
GNIS-catalogued hot spring on the Arizona side of the Colorado River in Black Canyon, Lake Mead NRA, just south of Hoover Dam near Lost Man Canyon — a real but minor thermal feature: a hot stream at river level with no soaking pool. NOTE: in Arizona, not California. Fee: Lake Mead NRA fees may apply. Off-trail technical terrain with dryfalls; extreme desert heat; no services.
Lost Man Hot Spring is a GNIS-catalogued thermal feature at river level where Lost Man Canyon meets the Colorado River, in the Black Canyon of the Colorado on the Arizona side of Lake Mead National Recreation Area, just south of Hoover Dam. Unlike nearby Arizona (Ringbolt) Hot Springs, it offers no soaking pool — a hiker who descended the canyon found simply a small stream of hot water emerging at the river's edge. The spring is most often reached by kayak or boat along the Black Canyon; the overland approach from the Kingman Wash parking area is an unmaintained Class 2/3 descent past dryfall obstacles, with Liberty Bell Arch visible en route and Boy Scout Canyon directly across the river.
Directions & trailhead access
Access is restricted; do not use historical directions to plan a visit.
Arizona geothermal context
Arizona's hot springs are products of Basin and Range crustal stretching, surfacing mostly along rugged canyon country around the Verde and Gila rivers. Many sit at the bottom of steep desert drainages where monsoon storms (July–September) can trigger flash floods. Desert heat makes winter the comfortable soaking season for most sites.
What a primitive site means here
Primitive springs have no facilities: no changing rooms, no trash service, often no maintained road to the pool. Expect natural rock or gravel bottoms, water temperature that varies by spot and season, and other visitors who may treat the site informally. Pack out everything you bring, test the water before entering, and leave the pool cleaner than you found it.
Fact sheet
| Source temp (historical) | Not reported |
|---|---|
| Trail access | Recorded coordinates — access unverified |
| Access fee | Fees reported |
| Geothermal data reference | NOAA Thermal Springs List (1980 archive) |
| Check land status | NPS — Hike the Arizona Hot Springs Trail (Lake Mead NRA) |
Lost Man Hot Spring FAQ
Is Lost Man Hot Spring open right now?
Wild thermal seep in Lost Man Canyon on the Arizona side of Lake Mead NRA just below Hoover Dam — a real hot spring but only a small stream of hot water with NO soakable pool; reached by kayak/boat on the Colorado River or by a hard Class-3 off-trail canyon scramble from the Kingman Wash parking area, and NPS bans damming the flow to build pools. (Status verified against an official source, last checked May 2026.)
Can I soak at Lost Man Hot Spring?
Wild thermal seep in Lost Man Canyon on the Arizona side of Lake Mead NRA just below Hoover Dam — a real hot spring but only a small stream of hot water with NO soakable pool; reached by kayak/boat on the Colorado River or by a hard Class-3 off-trail canyon scramble from the Kingman Wash parking area, and NPS bans damming the flow to build pools.
Where can I check access to Lost Man Hot Spring?
Check NPS — Hike the Arizona Hot Springs Trail (Lake Mead NRA): https://www.nps.gov/thingstodo/hike-the-arizona-hot-springs-trail.htm
Sources & references
- NPS — Hike the Arizona Hot Springs Trail (Lake Mead NRA) — official · 2026-05
- 8 News Now (KLAS) — Lake Mead amoeba warning as hot-springs trails reopen; lists Lost Man among AZ-side springs — news · 2025-10
- Stav is Lost — Lone Palm and Lost Man Hot Springs Loop trip report — community · 2020-12
- RoamFound — Lost Man Hot Spring GNIS entry — community · 2025
Details above were verified against the named sources on their listed dates — conditions change, so recheck before traveling. · How we verify our data · Report a correction