Mollys Hot Spring

Valley County, Idaho · Near Cascade
44.6420°N, 115.6930°W · 5,180 ft
138°F 32°F air · Good soaking weather 5,180 ft Open Roadside US Forest Service Camping nearby (1.2 mi)
Aerial view of the ground around Mollys Hot Spring LiDAR bare-earth view of the same ground around Mollys Hot Spring
Aerial LiDAR bare earth

Drag the handle to compare the two views. The orange dot marks the spring, in a frame about three quarters of a mile wide.

Nineteen or twenty miles from Cascade in Valley County, Idaho, Mollys Hot Spring is a Boise National Forest thermal source. The access status on record is open. The water is very hot, a few degrees shy of scalding, which means it burns and needs cooling before any soak. A 1980 sample put the pH high.

Location

South Fork Road runs close, a few hundred feet from the spring, so this counts as roadside. National Forest land and nothing more specific in the designation. The snowfall on record is enormous, nearly seventeen feet in an average winter, and the year is very wet. Mid elevation, cool average temperature, and a campground not far along the road.

Winter is listed as best, which given the snow would be a serious undertaking. Picnic Point campground is a little over a mile away. Treat the water as scalding; it is close enough to that line that the difference hardly matters. Test from the edge. The chemistry reading is over forty years old.

Terrain

Aircraft with laser scanners measured this ground to within inches. The scan strips out trees and buildings, leaving the bare shape of the land around Mollys Hot Spring.

Setting
Canyon floor
Steep ground climbs away on both sides of the spring.
Highest ground nearby
435 ft above the spring
Within a quarter mile, to the west
Cross-section through the spring

A slice through the ground from west to east, about 0.6 miles end to end.

Elevation data: USGS 3D Elevation Program. Aerial imagery: USGS The National Map. Public domain.

Heat Below
129 milliwatts per square meter of heat flow

That's about twice the US average of 65. It's higher than at 79% of the springs on this site.

Heat flow measures the warmth working its way up through the ground from deep inside the earth. Where it runs high, rain and snowmelt that seep down through cracks in the rock come back up hot.

Heat flow estimate: Stanford Thermal Earth Model (Aljubran & Horne, 2024), CC BY 4.0.

Monthly Climate
26°
Jan
27°
Feb
33°
Mar
37°
Apr
45°
May
55°
Jun
67°
Jul
67°
Aug
57°
Sep
43°
Oct
31°
Nov
23°
Dec
Annual Precip: 38.5 in Annual Snow: 198.7 in
Best Time to Visit
December Air 23°F · Water 138°F · +115° contrast
January Air 26°F · Water 138°F · +112° contrast
February Air 27°F · Water 138°F · +111° contrast
December offers 44°F more contrast than August
Current Conditions
32°F
Clear N 0.0 mph 93% Good soaking weather
Today 67° Low 39° Sunny
Spring is +71° warmer
Wednesday 75° Low 44° Sunny 2% precip
Spring is +63° warmer
Thursday 68° Low 42° Rain Showers 83% precip
Spring is +70° warmer
Friday 67° Low 41° Chance Rain Showers 45% precip
Spring is +71° warmer
Saturday 71° Low 42° Sunny 7% precip
Spring is +67° warmer
Water Chemistry Sampled 1980-06-06

The water at Mollys Hot Spring is alkaline (pH 9.3).

pH 9.3 Alkaline
pH influences mineral absorption through skin
Calcium 2 mg/L
May support bone density and joint health
Sodium 76 mg/L
Supports circulation and skin hydration
Sulfate 15 mg/L
Traditionally used for skin conditions and inflammation
Chloride 9 mg/L
Natural antiseptic with skin health benefits
Nearby Camping
Nearby Camping
Picnic Point (Id) 1.2 mi away

Overview Picnic Point Campground is located on a bluff overlooking beautiful Warm Lake, at an elevation of 5,300 feet. Visitors enjoy boating, fishing, swimming, hiking and viewing local wildlife. Recreation Warm Lake offers great fishing opportunities for cutthroat, rainbow, lake and bull trout. Boating, canoeing and swimming are popular activities. A boat ramp is located at neighboring Shoreline Campground. Billy Rice Swim Beach is within walking distance, offering a day-use site for picni...

Reservable Yes
Reserve on Recreation.gov →
Temperature
138°F
Warm Hot Boiling
Water Temp 138°F (59°C)
Avg Air Temp 43°F
Above Ambient +95°F
Great soaking conditions September
Access
Open
Road Access Roadside
Nearest Road South Fork Road
Distance to Road 279 ft
Land
Ownership Federal
Agency US Forest Service
Designation National Forest
Unit Boise National Forest
Manager US Forest Service
Protection 3 - Protected, subject to extractive use
Frequently Asked Questions
What is the water temperature at Mollys Hot Spring?
Mollys Hot Spring has a water temperature of 138°F (59°C). This is considered a hot spring, well above body temperature.
Where is Mollys Hot Spring located?
Mollys Hot Spring is located in Valley County, Idaho at 5,180 feet elevation, near Cascade. Coordinates: 44.6420°N, 115.6930°W.
How do I get to Mollys Hot Spring?
Mollys Hot Spring has Roadside road access, with the nearest road being South Fork Road (279 ft from the road).
Is Mollys Hot Spring free to visit?
Mollys Hot Spring has Open access. It is managed by US Forest Service.
Can I camp near Mollys Hot Spring?
Yes, Picnic Point (Id) is located nearby (1.2 miles away).
What minerals are in the water at Mollys Hot Spring?
Water chemistry analysis shows the presence of pH, Calcium, Sodium, Sulfate, Chloride. The pH is 9.3 (alkaline).
Is it safe to soak at Mollys Hot Spring?
With care. At 138°F Mollys Hot Spring is hot enough to need short sessions, fifteen to twenty minutes, and plenty of water. Enter slowly and get out if you feel light-headed.