Radium Hot Springs (Radium Warm Springs)

What to expect

Radium Hot Springs is a single rock-lined pool on the bank of the Colorado River, in the canyon country between Kremmling and State Bridge. The Bureau of Land Management calls it Radium Warm Springs, which is the more honest name. The water is warm, not hot. Visitor guides put the pool at roughly 80-90°F27-32°C, because cold river water seeps into it. One 2026 guide says the source is close to 97°F36°C and that the pool can reach the mid 90s in late summer when the river is low.

The pool sits right against a canyon wall at the river’s edge. One recent guide describes it as about 10 by 18 feet and around 2 feet deep, with a sandy bottom inside a ring of rocks. It holds a small group at most. The pool can also be reached by raft, so you may share it with people who arrived by boat.

There are no facilities at the pool: no toilets, no changing area and no drinking water. Bring what you need and carry out everything.

Getting there

The springs are in Grand County near the tiny settlement of Radium, about 20 miles from Kremmling by road. The last stretch is on dirt.

Access has changed. Older guides send you from the Mugrage site or the Radium Recreation Area along a social trail on Radium Road. That route is closed. The BLM says the Colorado Parks and Wildlife Mugrage site, including its restroom and the social trail to the springs, is closed to protect habitat, and BLM social trails along Radium Road are closed and under restoration, partly for bighorn sheep. There is currently no designated access to the springs from the recreation area, although the BLM is studying a future trail.

The route the BLM recommends now:

1. From Kremmling, drive south on Colorado Highway 9 for about 2 miles and turn west onto Trough Road (Grand County Road 1). Trough Road is part of the Colorado Headwaters Scenic and Historic Byway and much of it is dirt.
2. Follow Trough Road toward Radium. At the Radium Road and Trough Road intersection, look for the directional sign for Warm Springs Road.
3. Continue about 1.5 miles northeast along Trough Road to Warm Springs Road and follow it to the parking area and trailhead at its end.
4. From the trailhead, take the Warm Springs Trail (foot travel only) or the Ol’ Warm Springs Trail (open to foot, horse, bike and e-bike).

From the west, Trough Road also connects to State Bridge, and Rancho Del Rio, a private resort with a store and a fee river access, is about 6 miles west of the Radium Recreation Area on Trough Road.

Do not park on Radium Road between the recreation area and Trough Road. The BLM bans parking on this narrow stretch so emergency vehicles can get through.

The BLM does not publish a distance for the new trails. One guide describes the trail from the new lot as short and easy. Older accounts of the final approach describe a steep scramble of roughly 50 feet down a rock chute to the water, using handholds and footholds. Expect at least some rough ground at the end and wear shoes with grip.

When to go

July to early October is the window. Spring runoff on the Colorado River usually runs from May into June, and high water can flood the pool completely. Check river flows before you drive out early in the season. After runoff, the pool settles and warms up.

Weekday mornings are quietest. Summer weekends bring both car visitors and boaters, and the pool is small.

Winter is possible, but the water is only warm, and the campground at the Radium Recreation Area is closed from December 1 to March 31. Trough Road is dirt, so check conditions after snow.

Rules and etiquette

• Use designated routes only. Stay off the closed Mugrage social trail and the restored areas along Radium Road. These closures protect bighorn sheep habitat, and the BLM is asking visitors to respect them.
• No parking on Radium Road between the recreation area and Trough Road.
• Fees: There is no fee for the springs. The BLM charges day-use and camping fees at the Radium Recreation Area from April 1 to November 30. Colorado State Parks passes are not valid at this federal fee area.
• Clothing: No rule is posted for the springs in the sources we checked. Boaters can reach the pool, so a swimsuit is the safer choice.
• No cliff jumping. Guides warn against jumping from the rocks above the river.
• Pack it out. There are no trash cans at the pool.

Where to stay nearby

• Radium Recreation Area (BLM): 16 single sites and 2 group sites next to the Colorado River. All sites must be reserved on Recreation.gov. Single sites are $25 a night (up to 10 people, 2 vehicles) and group sites $75 (up to 30 people). Sites have picnic tables, fire rings, vault toilets and trash service, but no drinking water, hookups or cell service. The campground is closed December 1 to March 31. Stays are capped at 7 days from April through August and 14 days from September through November.
• Kremmling, about 20 miles east, has motels, fuel and groceries.
• Hot Sulphur Springs Resort & Spa, farther east in Grand County, is the nearest developed soak with lodging.

Safety notes

• The river: The Colorado is cold and powerful here, especially in runoff. Do not swim out from the pool, and keep a close eye on anyone who is not a strong swimmer.
• Cliff jumping: People have jumped from the rocks above the pool. Guides advise against it, because depth and current change with river levels.
• The descent: Where the route drops to the water, the footing is steep rock. Take it slowly, especially when wet, and do not attempt it in flip-flops.
• Remote area: There is no cell service at the recreation area without a booster. Download directions and tell someone your plan.
• Wildlife: This is bighorn sheep habitat. Give animals room and keep dogs under control.
• Summer heat: The canyon gets hot and exposed. Carry plenty of water, because none is available at the springs or the campground.