Billy Hot Spring

Valley County, Idaho · Near Cascade
44.7700°N, 115.6630°W · 5,790 ft
Hot 34°F air · Good soaking weather 5,790 ft Open Short Walk US Forest Service Camping nearby (8.0 mi)
Aerial view of the ground around Billy Hot Spring LiDAR bare-earth view of the same ground around Billy 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.

Valley County, Idaho, twenty-six miles from Cascade, on Payette National Forest land close to South Fork Salmon River Road: that is where you find Billy Hot Spring. Recorded as hot, no temperature given. A 1980 water sample shows a strongly alkaline pH. Open access. Under a mile of walking from the road. Shoreline is the campground in the record, eight miles away.

Location

Snow is the defining number here: over sixteen feet in a winter, with a wet year overall. Elevation is near fifty-eight hundred feet. Forest Service land, no further designation. From South Fork Salmon River Road it is a short walk, eight tenths of a mile by the record.

No best months, no temperature on file. Sixteen feet of snow will sit on this country for a good part of the year. Shoreline is the camping option on record. The spring is recorded as hot; test before touching. Alkaline water from a 1980 sample is all the chemistry there is. Open access.

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 Billy Hot Spring.

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

A slice through the ground from northwest to southeast, about 0.6 miles end to end.

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

Heat Below
93 milliwatts per square meter of heat flow

That's about 1½ times the US average of 65. It's higher than at 36% 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
23°
Jan
24°
Feb
30°
Mar
35°
Apr
42°
May
53°
Jun
65°
Jul
65°
Aug
55°
Sep
40°
Oct
28°
Nov
20°
Dec
Annual Precip: 37.9 in Annual Snow: 195.8 in
Current Conditions
34°F
Clear N 0.0 mph 93% Good soaking weather
Tuesday 69° Low 39° Sunny
Wednesday 76° Low 43° Sunny 2% precip
Thursday 70° Low 48° Rain Showers 83% precip
Friday 69° Low 46° Chance Rain Showers 46% precip
Saturday 72° Low 44° Sunny 7% precip
Water Chemistry Sampled 1980-06-05

The water at Billy Hot Spring is alkaline (pH 9.7).

pH 9.7 Alkaline
pH influences mineral absorption through skin
Calcium 2 mg/L
May support bone density and joint health
Magnesium 0 mg/L
Known for muscle relaxation and stress relief
Sodium 72 mg/L
Supports circulation and skin hydration
Sulfate 32 mg/L
Traditionally used for skin conditions and inflammation
Chloride 10 mg/L
Natural antiseptic with skin health benefits
Nearby Camping
Nearby Camping
Shoreline 8.0 mi away

Overview Shoreline Campground is located just across the road from 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. Billy Rice Swim Beach is nearby, offering a day-use site for picnicking and swimming. A boat ramp is located just across the road from the camp...

Reservable Yes
Reserve on Recreation.gov →
Mile-High Advisory 5,790 ft

Billy Hot Spring sits at 5,790 feet above sea level, way above the mile-high mark. You may not feel the altitude strongly, but hot water still dehydrates you faster at elevation. UV is about 23% stronger than at sea level, so bring sunscreen and drink more water than you normally would.

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Temperature
Hot
Warm Hot Boiling
Avg Air Temp 40°F
Access
Open
Road Access Short Walk
Nearest Road South Fork Salmon River Road
Distance to Road 0.8 mi
Land
Ownership Federal
Agency US Forest Service
Designation National Forest
Unit Payette National Forest
Manager US Forest Service
Protection 3 - Protected, subject to extractive use
Frequently Asked Questions
What is the water temperature at Billy Hot Spring?
Billy Hot Spring is classified as hot. An exact temperature measurement has not been recorded.
Where is Billy Hot Spring located?
Billy Hot Spring is located in Valley County, Idaho at 5,790 feet elevation, near Cascade. Coordinates: 44.7700°N, 115.6630°W.
How do I get to Billy Hot Spring?
Billy Hot Spring has Short Walk road access, with the nearest road being South Fork Salmon River Road (0.8 mi from the road).
Is Billy Hot Spring free to visit?
Billy Hot Spring has Open access. It is managed by US Forest Service.
Can I camp near Billy Hot Spring?
Yes, Shoreline is located nearby (8.0 miles away).
What minerals are in the water at Billy Hot Spring?
Water chemistry analysis shows the presence of pH, Calcium, Magnesium, Sodium, Sulfate, Chloride. The pH is 9.7 (alkaline).
Sources: USGS NWIS