Hot Lake Springs

Union County, Oregon · Near Union
45.2440°N, 117.9580°W
176°F 43°F air · Good soaking weather Roadside Camping nearby (13.7 mi)
Very Hot Source, Use Extreme Caution

At 176°F, the source water at Hot Lake 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.

Hot Lake Springs is the thermal spring behind the historic Hot Lake Hotel in Union County, Oregon, about five miles from the town of Union. The water is scalding at the source, well above anything you could sit in. The record has nothing on owner or access, though Wikipedia ties the spring to the hotel property, so expect the property to set the terms.

Location

The spring is a bit over a hundred feet off a road, at an elevation the record leaves blank. Moderate snow, moderate rain. Moss Springs Campground, around fourteen miles off, is the one campground listed.

Winter is marked as best. Do not touch the source water; it is hot enough to cause serious burns. Access is not on file, and this is a historic hotel property, so go in expecting the hotel to govern access. Camping is a drive away at Moss Springs.

History of Hot Lake Springs

Hot Lake Hotel, also called Hot Lake Sanatorium and Hot Lake Resort, is a Colonial Revival building first put up in 1864 and named for the thermal spring on its grounds. Around the turn of the twentieth century it ran as a luxury resort and sanatorium, advertising the medicinal qualities of the mineral water and drawing visitors from around the world, according to Wikipedia.

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 Hot Lake Springs.

Aerial view of the ground around Hot Lake Springs LiDAR bare-earth view of the same ground around Hot Lake 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
Hillside
The spring sits on a steep slope that climbs to the southwest.
Highest ground nearby
523 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
67 milliwatts per square meter of heat flow

That's close to the US average of 65. It's higher than at 3% 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
30°
Jan
32°
Feb
39°
Mar
46°
Apr
55°
May
62°
Jun
72°
Jul
72°
Aug
63°
Sep
49°
Oct
37°
Nov
29°
Dec
Annual Precip: 28.9 in Annual Snow: 74.6 in
Best Time to Visit
December Air 29°F · Water 176°F · +147° contrast
January Air 30°F · Water 176°F · +146° contrast
February Air 32°F · Water 176°F · +144° contrast
December offers 43°F more contrast than August
Current Conditions
43°F
S 29.1 mph 93% Good soaking weather
Tuesday 71° Low 44° Partly Sunny 6% precip
Spring is +105° warmer
Wednesday 74° Low 47° Sunny 2% precip
Spring is +102° warmer
Thursday 73° Low 48° Chance Rain Showers 45% precip
Spring is +103° warmer
Friday 77° Low 48° Sunny 9% precip
Spring is +99° warmer
Saturday 80° Low 49° Sunny 1% precip
Spring is +96° warmer
Where to Stay

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Nearby Camping
Moss Springs Campground 13.7 mi away

Located above Cove, Oregon, the Moss Springs Campground lies on a ridgeline within view of the Eagle Cap Wilderness and is next to Moss Springs Trailhead. This popular campground was constructed to accommodate visitors with packstock, riding stock and campers bound for the wilderness. The site also has 3 accessible campsites and toilets. Trails from the campground drop steeply into the Minam River drainage or follow Grande Ronde Ridge.

Reserve on Recreation.gov →
Temperature
176°F
Warm Hot Boiling
Water Temp 176°F (80°C)
Avg Air Temp 49°F
Above Ambient +127°F
Great soaking conditions September
Access
Road Access Roadside
Distance to Road 145 ft
Frequently Asked Questions
What is the water temperature at Hot Lake Springs?
Hot Lake Springs has a water temperature of 176°F (80°C). This is considered a hot spring, well above body temperature.
Where is Hot Lake Springs located?
Hot Lake Springs is located in Union County, Oregon, near Union. Coordinates: 45.2440°N, 117.9580°W.
How do I get to Hot Lake Springs?
Hot Lake Springs has Roadside road access (145 ft from the road).
Can I camp near Hot Lake Springs?
Yes, Moss Springs Campground is located nearby (13.7 miles away).
Is it safe to soak at Hot Lake Springs?
No, not at the source. The water at Hot Lake Springs reaches 176°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: Wikipedia