Loftus Hot Spring
Loftus Hot Spring pours out at 129 degrees Fahrenheit directly beside Middle Fork Road in the Boise National Forest, just 23 meters from pavement. Its alkaline pH of 9.6 makes it one of the more caustic springs in the drainage, and the sodium-dominated chemistry reflects deep circulation through the Idaho Batholith's granite core.
The Middle Fork Boise River canyon narrows here at 3,630 feet, where steep, forested slopes channel the river through exposed rock. The spring emerges near river level, and on cool mornings, steam hangs in the canyon like fog. Ponderosa pine and Douglas fir line the slopes above, and the sound of the river is constant. The area receives 29 inches of precipitation and 110 inches of snow annually, creating a green, damp canyon that contrasts sharply with the high desert just miles away.
This stretch of the Middle Fork Boise River cuts through the Idaho Batholith, a massive Cretaceous-age granite intrusion. Hot water rises along fractures in this granite, picking up sodium and shedding calcium in the alkaline conditions deep underground. Nearby Ninemeyer Campground lost all its amenities to wildfire -- no developed fire rings remain, and Stage 1 fire restrictions prohibit campfires entirely when in effect.
Roadside access makes this one of the easiest hot springs to reach along the Middle Fork corridor. The source temperature of 129 degrees is dangerous for direct contact -- look for spots where river water mixes in. The road is passable by car in good weather from mid-May through late September but becomes rough in spots. Ninemeyer Campground, 4.6 kilometers away, is free and first-come, first-served but currently has no amenities due to fire damage.
Is Loftus Hot Spring worth visiting?
Best for
- Hot spring soaking
- Easy day trips
- Overnight camping trips
The water at Loftus Hot Spring is alkaline (pH 9.6).
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Overview:Due to a wildfire, there are no amenities at the campground. Currently there are no developed campfire rings therefore when Stage 1 fire restrictions area in effect, no fires are permitted.A stay at Ninemeyer Campground enables guests to enjoy all the beauty and recreation offered along the (Middle Fork Boise River Road) Forest Service (FS) Road 268. Weather is usually good from mid-May through late September and is easily accessible by car in good weather, although the road is some...