Radium Hot Springs
By the HotSpringsFind editorial team · How we compile records · Reviewed September 2026
Radium Hot Springs is a primitive hot spring listed near Kremmling, Colorado. Reported soak temperature: 95°F. See the visit fact sheet.
Stop on Colorado Hot Springs Loop — see all stops, ordered south to north.
Current status
Free primitive BLM warm spring on the Colorado River ~15 mi southwest of Kremmling — a rock-lined pool (~10×18 ft, ~2 ft deep, 80–97°F) perched on a ledge up the canyon wall, reached only via the Warm Springs Road trailhead off Trough Road (CR-1) then a ~0.75–1.5 mi hike ending in a ~50-ft rock-chimney descent on footholds; the old Mugrage site trail on Radium Road is CLOSED for wildlife habitat and parking on Radium Road is banned — use only the signed Warm Springs Road trailhead.
Checked September 2026 · verified against an official source · 5 sources ↓
Before you go
- Status: Road access restricted — confirm via BLM — Radium Recreation Area official page (Mugrage site closed, no parking on Radium Rd, Warm Springs Road trailhead directions, Warm Springs Trail / Ol' Warm Springs Trail).
- Cost: Reported free access — fees and permits can change, confirm before visiting.
- Getting there: Reported 0.75 mi trail — confirm the route, road, and seasonal access.
- Water: Reported soak temperature 95°F — always test the water before entering.
- Rules: Reported clothing required; reported dog-friendly.
- Conditions: check weather, fire closures, and land-manager alerts the week you go — mountain access changes seasonally.
- Reservations/permits: None — free day use on BLM land (Upper Colorado River SRMA); camping at Radium Recreation Area is fee-based via recreation.gov.
- Best time to go: Late summer through fall when river levels are lowest (the pool is warmest when the river is lowest); midweek mornings for solitude — summer weekends are the busiest.
- Clothing reality: No official clothing rule — BLM public land; mix of suited and nude soakers is customary, suits common on busy river-season days.
- Kids: Allowed.
- Cell service: none — download maps and tell someone your plan.
- Accessibility: NOT accessible — plateau hike plus a steep rock-chimney scramble down the canyon wall.
- ACCESS CHANGE: the Mugrage site trail on Radium Road (the historic route) is CLOSED by Colorado Parks & Wildlife for bighorn habitat protection — do not park on Radium Road/CR-11; use the Warm Springs Road trailhead 0.9 mi off Trough Road
- The pool sits on a ledge reached by descending a ~50-ft rock chimney on carved footholds/handholds — a real scramble; not for small kids or anyone unsteady
- Pool floods with cold river water at high flows — roughly March through late May the soak can be submerged/tepid depending on snowmelt
- Pool is small (~10×18 ft) and holds only 10–20 people — summer weekends pack it with rafters, kayakers and campers
- Warm Springs Road is unpaved and impassable in snow — in winter park at CR-1/Trough Rd and hike in farther
- No facilities at the spring; vault toilets, campsites and boat ramps are at the Radium Recreation Area downriver
- Cell service unreliable at the trailhead — download maps in advance
- Cliff jumping into the river below the pool happens here — rocks and shallow water make it genuinely dangerous
- Hazard: ~50-ft near-vertical rock chimney descent — falls are the primary risk; wet rock makes it slicker
- Hazard: Pool floods in spring runoff — cold-water exposure
- Hazard: Cliff jumping into the Colorado River has caused injuries — water depth and rocks are unmarked
- Hazard: Remote canyon — no cell service, nearest help in Kremmling
- Hazard: Rattlesnakes and bighorn sheep habitat — watch footing and give wildlife space
About this spring
Primitive warm spring on the Colorado River in the BLM Radium Recreation Area, ~15 miles southwest of Kremmling. A single rock-lined pool (~10x18 ft) sits on a ledge partway up the canyon wall — popular post-float stop for Gore Canyon rafters. River mixing keeps water lukewarm (~80-97°F); the pool submerges during high flows. Former Mugrage Campground access on Radium Road is CLOSED. Pool flooded/unusable during spring runoff. Steep scramble descent.
Radium Hot Springs is a single primitive, rock-lined pool — roughly 10 by 18 feet and about two feet deep with a sandy bottom — set on a ledge partway up the Colorado River canyon wall at about 6,800 feet in the BLM's Radium Recreation Area, part of the Upper Colorado River Special Recreation Management Area. The source runs near 97°F, but mixing with river water keeps the pool lukewarm, typically in the low 80s to mid 90s, and high flows can submerge it entirely. The name comes from the nearby settlement of Radium, a relic of early-1900s radium and uranium prospecting. The old access via the Colorado Parks and Wildlife Mugrage site on Radium Road is closed to protect bighorn sheep habitat; BLM now routes visitors to the Warm Springs Road trailhead, where the foot-only Warm Springs Trail (about 0.75 miles) or the multi-use Ol' Warm Springs Trail leads to the canyon rim, followed by a steep ~50-foot rock-chimney scramble down to the water. It is a traditional post-float stop for Gore Canyon rafters.
Directions & trailhead access
From Kremmling, CO-9 south ~2 mi to Trough Road (CR 1), west ~12-14 mi to Warm Springs Road, 0.9 mi to the signed trailhead; hike the Warm Springs Trail ~0.75 mi to the pool.
Colorado geothermal context
Colorado's springs rise along fault zones threading the Rocky Mountains — the same tectonics that built the ranges drive deep groundwater circulation. Many sites sit above 7,000 feet, so snowpack closes roads and trailheads well into late spring, and afternoon thunderstorms are routine in summer. Resort valleys like Steamboat, Pagosa, and Ouray anchor the developed end of the spectrum.
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.
Best time to visit
June – September (Late Spring through Early Autumn)High-altitude mountain access routes and backcountry trailheads can experience seasonal snowpack from November through May. Peak summer and early autumn provide clear trail access and pleasant evening soak conditions.
Fact sheet
| Reported soak temp | 95°F |
|---|---|
| Source temp (historical) | 98°F |
| Hiking distance | 0.75 miles (moderate) |
| Access fee | Reported free — verify locally |
| Clothing policy | Reported clothing required |
| Pet policy | Reported dog-friendly |
| Geothermal data reference | NOAA Thermal Springs List (1980 archive) |
| Check land status | BLM — Radium Recreation Area official page (Mugrage site closed, no parking on Radium Rd, Warm Springs Road trailhead directions, Warm Springs Trail / Ol' Warm Springs Trail) |
Radium Hot Springs FAQ
Is Radium Hot Springs open right now?
Free primitive BLM warm spring on the Colorado River ~15 mi southwest of Kremmling — a rock-lined pool (~10×18 ft, ~2 ft deep, 80–97°F) perched on a ledge up the canyon wall, reached only via the Warm Springs Road trailhead off Trough Road (CR-1) then a ~0.75–1.5 mi hike ending in a ~50-ft rock-chimney descent on footholds; the old Mugrage site trail on Radium Road is CLOSED for wildlife habitat and parking on Radium Road is banned — use only the signed Warm Springs Road trailhead. (Status verified against an official source, last checked September 2026.)
Is Radium Hot Springs free?
Radium Hot Springs is listed as free to access in Grand County, Colorado. Fees and rules change — verify current status with the land manager before visiting.
What temperature is Radium Hot Springs?
Radium Hot Springs has a reported soak temperature of 95°F and a historical source temperature of 98°F in survey records. Historical data may not reflect current conditions — always test water before entering.
Is Radium Hot Springs clothing optional?
Radium Hot Springs is listed as swimsuit-required in directory records. Confirm current rules before visiting, as policies change.
How far is the hike to Radium Hot Springs?
The hike to Radium Hot Springs near Kremmling, Colorado is a 0.75-mile walk (moderate) from the designated vehicle access area, per public trail records.
Sources & references
- BLM — Radium Recreation Area official page (Mugrage site closed, no parking on Radium Rd, Warm Springs Road trailhead directions, Warm Springs Trail / Ol' Warm Springs Trail) — official · 2026-09
- Recreation.gov — Radium Recreation Area (same BLM access notice; campground details) — official · 2026-09
- Hot Springs Guides — Radium Hot Springs (pool ~97°F source, 10×18 ft, chimney descent, seasonal flood window) — community · 2026-04
- AllTrails — Radium Hot Springs trail (1.5-mi loop, scrambling, dog policy, winter road note) — community · 2026-07
Additional references for this record; a source link does not guarantee current conditions.
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
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