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Lower Loon Creek Hot Spring emerges at 120 degrees Fahrenheit along Loon Creek in the Challis National Forest, one of central Idaho's most remote drainages. Known locally as Loon Creek Hot Spring, it sits at 4,094 feet with alkaline water (pH 9.0) and a sodium concentration of 94 milligrams per liter -- among the highest in the region.
Loon Creek Canyon is deep backcountry. At 577 meters from the nearest road, the spring requires a real walk through forest and along the creek, which runs clear and cold past rock walls and stands of ponderosa pine. The elevation here is moderate at 4,094 feet, but the surrounding ridges climb thousands of feet higher, catching 102 inches of snow each winter. The air averages 47 degrees annually, and the canyon stays cool even in summer. Steam rises from the spring's source and drifts through the trees, marking the location from a distance.
History of Lower Loon Creek Hot Spring
Loon Creek cuts through Cretaceous granite of the Idaho Batholith, and the hot springs along its length emerge where faults intersect the creek drainage. The sodium-dominated, low-calcium chemistry (1.8 mg/L calcium versus 94 mg/L sodium) indicates deep circulation through granite, likely exceeding several kilometers of depth. Yellowjacket Guard Station, a historic 1925 Forest Service ranger station remodeled by the CCC in 1934, offers reservable lodging 34 kilometers away and is eligible for the National Register of Historic Places.
Access requires a walk of nearly 600 meters from the road, through terrain that can be slippery near the creek. Water at 120 degrees needs cooling before soaking -- find where creek water enters the thermal pools. This area is remote with limited cell service and rough roads that may require high clearance. Yellowjacket Guard Station, 34 kilometers away, can be reserved and offers shelter and basic facilities. Plan for seasonal access only, roughly June through October.
Is Lower Loon Creek Hot Spring worth visiting?
Best for
- Hot spring soaking
- Overnight camping trips
Lower Loon Creek Hot Spring is well suited for hot spring soaking and overnight camping trips.
Annual Precip: 22.5 in
Annual Snow: 101.9 in
December
Air 25°F · Water 120°F · +95° contrast
January
Air 28°F · Water 120°F · +92° contrast
February
Air 30°F · Water 120°F · +90° contrast
December offers 48°F more contrast than July
Recent Temperature
121.1°F
(49.5°C)
Measured Jun 28, 1980
The water at Lower Loon Creek Hot Spring is alkaline (pH 9.0).
pH influences mineral absorption through skin
May support bone density and joint health
Supports circulation and skin hydration
Traditionally used for skin conditions and inflammation
Natural antiseptic with skin health benefits
Overview
Yellowjacket Guard Station is a historic Forest Service Ranger Station and Work Center. Originally constructed in 1925 and remodeled in 1934 by the Civilian Conservation Corps, the structure is eligible for listing on the National Register of Historic Places. Recreation
Hikers, horseback riders, mountain bikers and off-road enthusiasts will find many trails in the surrounding area. Hunting is also a popular activity. Click here for an Idaho OHV safety messageFacilities
The spacious...
Reserve on Recreation.gov →
Swimsuit & towel
Water bottle
Stay hydrated, especially in hot water
Camping gear
Nearby camping at Yellowjacket Guard Station
Trash bag
Pack out what you pack in
Water shoes
Hot ground near source
37 miles from Challis, ID
USGS Quad: RAMEY HILL 7.5 · PP 492: 55.0 · NOAA: 4.0 · AMS Map: CHALLIS
What is the water temperature at Lower Loon Creek Hot Spring?
Lower Loon Creek Hot Spring has a water temperature of 120°F (49°C). This is considered a hot spring, well above body temperature.
Where is Lower Loon Creek Hot Spring located?
Lower Loon Creek Hot Spring is located in Custer County, Idaho at 4,094 feet elevation, near Challis. Coordinates: 44.7990°N, 114.8060°W.
How do I get to Lower Loon Creek Hot Spring?
Lower Loon Creek Hot Spring has Short Walk road access (0.4 mi from the road).
Is Lower Loon Creek Hot Spring free to visit?
Lower Loon Creek Hot Spring has Open access. It is managed by US Forest Service.
Can I camp near Lower Loon Creek Hot Spring?
Yes, Yellowjacket Guard Station is located nearby (20.8 miles away).
What minerals are in the water at Lower Loon Creek Hot Spring?
Water chemistry analysis shows the presence of pH, Calcium, Sodium, Sulfate, Chloride. The pH is 9.0 (alkaline).
Is it safe to soak at Lower Loon Creek Hot Spring?
At 120°F, Lower Loon Creek Hot Spring is hot enough to require caution. Enter slowly, limit soaking sessions to 15–20 minutes, and stay hydrated. Always tell someone your plans before visiting remote hot springs.
Is Lower Loon Creek Hot Spring crowded?
Lower Loon Creek Hot Spring sees varying levels of visitors depending on the season and day of the week.
What should I bring to Lower Loon Creek Hot Spring?
Essentials for Lower Loon Creek Hot Spring: swimsuit, towel, water bottle, camping gear, a trash bag to pack out what you pack in. The water is over 110°F — test the temperature before entering and watch for scalding near the source.