Guyer Hot Springs

Blaine County, Idaho · Near Ketchum
43.6840°N, 114.4100°W · 5,920 ft
158°F 39°F air · Good soaking weather 5,920 ft Roadside Camping nearby (7.3 mi)
Very Hot Source, Use Extreme Caution

At 158°F, the source water at Guyer 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.

Guyer Hot Springs comes up about two miles outside Ketchum in Blaine County, Idaho, close enough to town that it barely counts as a drive. The water is the thing to know about. The survey on file puts it far above anything a person could sit in, hot enough to scald on contact. Public access at the source is not recorded, and no land owner is listed, so check on both before treating it as somewhere to visit.

Location

Warm Springs Road runs right past it, and the source sits a few steps off the pavement. You barely leave the car. This is mountain country around Ketchum, high enough that the winters are long and cold, and the snowfall on file is heavy, over nine feet in an average year. Summers stay short and fairly dry. Nobody has recorded who manages the ground around the spring.

The record lists winter as the best season. Do not put a hand in it. At the temperature on record this water will burn skin in seconds, and any soak would depend on cooling it, which nothing on file says is possible. North Fork is the closest campground in the record, roughly seven miles off. Check access before you go, since the public's standing at the source is unrecorded, and the chemistry reading dates to 1988.

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 Guyer Hot Springs.

Aerial view of the ground around Guyer Hot Springs LiDAR bare-earth view of the same ground around Guyer Hot Springs
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.

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

A slice through the ground from southwest to northeast, about 0.6 miles end to end.

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

Heat Below
92 milliwatts per square meter of heat flow

That's about 1½ times the US average of 65. It's higher than at 34% 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
22°
Jan
24°
Feb
30°
Mar
36°
Apr
45°
May
56°
Jun
67°
Jul
66°
Aug
56°
Sep
42°
Oct
29°
Nov
19°
Dec
Annual Precip: 23.4 in Annual Snow: 115.3 in
Best Time to Visit
December Air 19°F · Water 158°F · +139° contrast
January Air 22°F · Water 158°F · +136° contrast
February Air 24°F · Water 158°F · +134° contrast
December offers 48°F more contrast than July
Current Conditions
39°F
Clear NW 33.0 mph 75% Good soaking weather
Today 69° Low 41° Sunny
Spring is +89° warmer
Wednesday 75° Low 46° Sunny 13% precip
Spring is +83° warmer
Thursday 69° Low 41° Light Rain Likely then Showers And Thunderstorms 84% precip
Spring is +89° warmer
Friday 69° Low 40° Sunny then Slight Chance Light Rain 19% precip
Spring is +89° warmer
Saturday 71° Low 41° Sunny 5% precip
Spring is +87° warmer
Water Chemistry Sampled 1988-05-03

The water at Guyer Hot Springs is alkaline (pH 9.1).

pH 9.1 Alkaline
pH influences mineral absorption through skin
Calcium 2 mg/L
May support bone density and joint health
Magnesium 6 mg/L
Known for muscle relaxation and stress relief
Sodium 88 mg/L
Supports circulation and skin hydration
Sulfate 76 mg/L
Traditionally used for skin conditions and inflammation
Chloride 11 mg/L
Natural antiseptic with skin health benefits
Where to Stay

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Nearby Camping
North Fork (Id) 7.3 mi away

Overview North Fork Campground is situated on the banks of the beautiful Big Wood River at an elevation of 6,300 feet. Visitors enjoy fishing and tubing on the river and exploring the Harriman Trail.Recreation This site is part of the Sawtooth National Recreation Area, where outdoor activities abound. Fly-fishing for rainbow, brown and brook trout is popular on the Big Wood River, as is float tubing. The 20-mile Harriman Trail leads past the campground, offering excellent hiking and biking...

Reservable Yes
Reserve on Recreation.gov →
Mile-High Advisory 5,920 ft

Guyer Hot Springs sits at 5,920 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 24% stronger than at sea level, so bring sunscreen and drink more water than you normally would.

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Temperature
158°F
Warm Hot Boiling
Water Temp 158°F (70°C)
Avg Air Temp 41°F
Above Ambient +117°F
Great soaking conditions September
Access
Road Access Roadside
Nearest Road Warm Springs Road
Distance to Road 22 ft
Frequently Asked Questions
What is the water temperature at Guyer Hot Springs?
Guyer Hot Springs has a water temperature of 158°F (70°C). This is considered a hot spring, well above body temperature.
Where is Guyer Hot Springs located?
Guyer Hot Springs is located in Blaine County, Idaho at 5,920 feet elevation, near Ketchum. Coordinates: 43.6840°N, 114.4100°W.
How do I get to Guyer Hot Springs?
Guyer Hot Springs has Roadside road access, with the nearest road being Warm Springs Road (22 ft from the road).
Can I camp near Guyer Hot Springs?
Yes, North Fork (Id) is located nearby (7.3 miles away).
What minerals are in the water at Guyer Hot Springs?
Water chemistry analysis shows the presence of pH, Calcium, Magnesium, Sodium, Sulfate, Chloride. The pH is 9.1 (alkaline).
Is it safe to soak at Guyer Hot Springs?
No, not at the source. The water at Guyer Hot Springs reaches 158°F, which can cause severe burns within seconds. Look for cooled side pools or downstream stretches, and test with a hand before anything else.
Sources: USGS NWIS