Challis Hot Springs

What to expect

Challis Hot Springs is a plain, old-fashioned soaking pool in a wide valley on the Salmon River, a few miles outside the small ranching town of Challis. There is nothing fancy about it, and that is most of the appeal. You get two outdoor pools, cottonwoods along the river, bare hills on every side, and a campground where people stay for days.

The large pool measures 100 by 30 feet. It is warm rather than hot, kept at about 96°F36°C in summer and 98-100°F37-38°C in winter, so you can swim laps or float for an hour without overheating. The smaller pool, 25 by 18 feet, is the one regulars head for on cold nights. Staff aim to hold it at about 105°F41°C.

Both pools are fed by hot spring water that flows through without chemicals. One directory puts the source at about 127°F53°C. Because the only way to cool it is to mix in water from the campground well by hand, the temperature moves around through the day. The park itself says to enter carefully.

The springs have a long history. The Hammond family’s ancestors homesteaded the land and developed the springs in the late 1800s, and the place served miners heading to and from the gold camps of the Yankee Fork and Bayhorse between the 1880s and 1910s. In May 2023 the Idaho Department of Parks and Recreation finished buying the 104-acre property from the family. It is now the newest unit of Land of the Yankee Fork State Park, and the state has said it plans to upgrade the pools and expand the campground over time.

Getting there

Challis sits on US-93 in central Idaho, about where Highway 75 from Stanley meets US-93 from Salmon and Arco. The springs are northeast of town on the Salmon River.

From the junction of US-93 and Highway 75 near Challis, follow US-93 about 1.5 miles to Hot Springs Road. Turn onto Hot Springs Road and follow it about 2.7 miles, then bear left onto Challis Hot Springs Road for the last 2.4 miles. The entrance is on the left at 5025 Hot Springs Road. Signs point the way from the highway.

The roads are fine for any car or RV. Parking is right next to the pool building, so this is a roadside stop with no walking to speak of.

Rough driving times: Stanley is roughly an hour west on Highway 75 along the Salmon River, Salmon is about an hour north on US-93, and Idaho Falls is around three hours southeast.

When to go

The pools are open all year, which makes Challis one of the more reliable soaks in this part of Idaho. Each season feels different.

Winter is the best reason to come. Challis gets cold, dry winters, and sitting in the hot pool with steam lifting off the water and snow on the hills is the classic visit. Hours are shorter in winter. In past years the park has cut back to a Wednesday to Sunday schedule from November, so check before you go.

Spring and fall are pleasant and quieter. The campground opens for the season in mid-March, and fall brings hunters, anglers and river traffic but rarely crowds the pools.

Summer is busy with campers and families, and the hot pool can feel like too much on a 90°F32°C afternoon. Mornings and evenings are better. The pools close at the first sign of lightning and stay closed for 20 minutes after the last thunder, which happens often during summer storms.

Prices and booking

Pool entry and camping are handled by Idaho State Parks.

• Day use: $10 per person. Children 5 and under are free.
• Vehicle entry: The park-wide $7 motor vehicle entrance fee applies unless you display an Idaho State Parks Passport or an annual entrance sticker.
• Hours: Recently Tuesday to Sunday 8:30 a.m. to 8:30 p.m. and Monday 8:30 a.m. to 4:30 p.m. Winter hours are shorter.
• Camping reservations: Online through the Idaho State Parks booking site, or by phone at 1-888-922-6743. Pool day use does not need a booking.

House rules worth knowing:

• Swimsuits are required. This is a family pool.
• Under-18s must be accompanied and supervised by an adult the whole time.
• Lightning closes the pools. Staff clear the water when they see lightning or hear thunder.
• Pets are allowed in the park on a 6-foot leash, but not in the pools.

The old private operation had changing rooms and showers next to the pools, and the state has kept the facility running much as it was while it plans upgrades. Bring your own towel.

Where to stay nearby

Challis Hot Springs campground is the obvious choice. It has 68 sites, from primitive tent sites to RV sites with water and electric hookups, and a dump station. Standard sites allow one RV or camping unit, two vehicles, two tents and up to eight people. Companion sites take twice that. Book ahead for summer weekends and holidays. Rates are listed on the state parks booking site.

The state’s listing does not include cabins or rooms at the springs. For a bed, Challis has motels a few miles away. Stanley, roughly an hour west, has more lodging, and Mountain Village Resort there has its own geothermal soak for guests. Salmon, about an hour north, has the most services in the region.

Forest Service campgrounds line Highway 75 and the Yankee Fork west of Challis if you prefer something more rustic.

Safety notes

• Temperature drift: The pools are mixed by hand, so the hot pool can run above its 105°F41°C target. Test it before you sink in, keep soaks in the hot pool short, and drink water.
• Lightning: Storms build quickly over the valley in summer. Get out when staff call it.
• Children: The large pool is big and deep enough for swimming. Watch kids closely, as the rules require.
• Cold: Winter nights in Challis drop well below freezing. Bring warm layers and dry shoes for the walk back to the car or camper.
• The river: The Salmon runs past the campground. It is fast and cold in early summer, so keep an eye on kids near the bank.

Nearby stops worth adding

The Land of the Yankee Fork Interpretive Center, about two miles south of Challis, explains the gold rush that once filled this region and is part of the same state park. From there you can drive to the ghost towns of Bayhorse and Custer, the other main pieces of the park.

Heading west toward Stanley on Highway 75, the Salmon River canyon has several wild springs right off the road. Sunbeam Hot Springs has riverside pools and restrooms, and Basin Creek and Cove Creek (Kem) Hot Springs sit a few miles closer to Stanley. Many people pair a night at Challis with a day of soaking along that road.