At 158°F, the source water at Hot Springs is hot enough to cause burns. Some hot springs this hot have cooler side pools or downstream areas suitable for soaking — always test the water temperature before entering.
At 158 degrees Fahrenheit, this unnamed spring near Mountain Home runs far too hot for soaking but ranks among Elmore County's most thermally intense sources. It sits at 3,557 feet where the Snake River Plain meets rising foothills, its alkaline water carrying a pH of 9.4 and remarkably low calcium at just 0.4 mg/L.
The spring emerges in dry, open terrain typical of south-central Idaho's high desert transition zone, where sagebrush and bunchgrass cover the slopes. Annual rainfall barely reaches 15 inches, and winter brings light dustings of snow totaling around 32 inches. The air is dry and still. Steam rises visibly from the source, especially on cooler mornings when the 105-degree temperature differential between water and air is most pronounced.
History of Hot Springs
Geologically, this spring taps deep fracture systems along the northern margin of the Snake River Plain, where volcanic activity heated the underlying rock. The sodium-dominant, calcium-depleted chemistry and high pH point to prolonged contact with rhyolitic formations at depth. The 286 mg/L total dissolved solids suggest a moderately mineralized system with a long underground residence time.
The spring is a short walk of about 900 feet from the nearest road at 3,557 feet elevation. Water temperature makes direct contact dangerous. Spillway Campground on Anderson Ranch Reservoir sits 23 kilometers away and offers three first-come, first-served sites with fishing access for smallmouth bass and kokanee.
Is Hot Springs worth visiting?
Best for
Observing powerful hot springs
Overnight camping trips
Not ideal for
Casual soaking
Hot Springs is well suited for observing powerful hot springs and overnight camping trips.
Monthly Climate
29°Jan
34°Feb
43°Mar
50°Apr
59°May
70°Jun
80°Jul
79°Aug
68°Sep
52°Oct
40°Nov
29°Dec
Annual Precip: 15.1 inAnnual Snow: 32.4 in
Best Time to Visit
JanuaryAir 29°F · Water 158°F · +129° contrast
DecemberAir 29°F · Water 158°F · +129° contrast
FebruaryAir 34°F · Water 158°F · +124° contrast
January offers 51°F more contrast than July
USGS Field Measurements
Recent Temperature
158.0°F
(70.0°C)Measured Jul 30, 1957
Water ChemistrySampled 1957-07-30
The water at Hot Springs is alkaline (pH 9.4) with 286 mg/L total dissolved solids.
Overview: Spillway Campground is a small campground with 3 campsites along Anderson Ranch Reservoir. The reservoir is a popular destination for fishing, boating, waterskiing and riding personal watercraft. There is excellent fishing in the reservoir for smallmouth bass and kokanee. Also try your luck at fly fishing just below the dam for a trout!Rafting access is at Reclamation Village, just south of the campground.
Hot Springs has a water temperature of 158°F (70°C). This is considered a hot spring, well above body temperature.
Where is Hot Springs located?
Hot Springs is located in Elmore County, Idaho at 3,557 feet elevation, near Mountain Home. Coordinates: 43.1550°N, 115.5180°W.
How do I get to Hot Springs?
Hot Springs has Short Walk road access (0.2 mi from the road).
Can I camp near Hot Springs?
Yes, Spillway Campground is located nearby (14.4 miles away).
What minerals are in the water at Hot Springs?
Water chemistry analysis shows the presence of pH, Total Dissolved Solids, Calcium, Sodium, Sulfate, Chloride. The pH is 9.4 (alkaline). Total dissolved solids measure 286 mg/L.
Is it safe to soak at Hot Springs?
The water at Hot Springs reaches 158°F, which can cause severe burns. Do not enter the source pool directly — look for cooled side pools or downstream areas where the water has cooled to a safe temperature. Access may be on private land or unconfirmed — verify current conditions before visiting. Always tell someone your plans before visiting remote hot springs.
Is Hot Springs crowded?
Hot Springs sees varying levels of visitors depending on the season and day of the week.
What should I bring to Hot Springs?
Essentials for Hot Springs: 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.