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.
History of Loftus Hot Spring
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
Loftus Hot Spring offers an accessible hot spring experience — great for a day trip.
Annual Precip: 28.8 in
Annual Snow: 110.1 in
December
Air 28°F · Water 129°F · +101° contrast
January
Air 30°F · Water 129°F · +100° contrast
February
Air 32°F · Water 129°F · +97° contrast
December offers 47°F more contrast than July
Recent Temperature
131.0°F
(55.0°C)
Measured May 27, 1981
The water at Loftus Hot Spring is alkaline (pH 9.6).
pH influences mineral absorption through skin
May support bone density and joint health
Supports circulation and skin hydration
Traditionally used for skin conditions and inflammation
Natural antiseptic with skin health benefits
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...
Reserve on Recreation.gov →
Swimsuit & towel
Water bottle
Stay hydrated, especially in hot water
Camping gear
Nearby camping at Ninemeyer Campground
Trash bag
Pack out what you pack in
Water shoes
Hot ground near source
2 miles from Idaho City, ID
USGS Quad: SHEEP CREEK 7.5 · PP 492: 113.0 · NOAA: 13.0 · AMS Map: HAILEY
What is the water temperature at Loftus Hot Spring?
Loftus Hot Spring has a water temperature of 129°F (54°C). This is considered a hot spring, well above body temperature.
Where is Loftus Hot Spring located?
Loftus Hot Spring is located in Boise County, Idaho at 3,630 feet elevation, near Idaho City. Coordinates: 43.7240°N, 115.6040°W.
How do I get to Loftus Hot Spring?
Loftus Hot Spring has Roadside road access, with the nearest road being Middle Fork Road (76 ft from the road).
Is Loftus Hot Spring free to visit?
Loftus Hot Spring has Open access. It is managed by US Forest Service.
Can I camp near Loftus Hot Spring?
Yes, Ninemeyer Campground is located nearby (2.9 miles away).
What minerals are in the water at Loftus Hot Spring?
Water chemistry analysis shows the presence of pH, Calcium, Sodium, Sulfate, Chloride. The pH is 9.6 (alkaline).
Is it safe to soak at Loftus Hot Spring?
At 129°F, Loftus Hot Spring is hot enough to require caution. Enter slowly, limit soaking sessions to 15–20 minutes, and stay hydrated. Always tell someone your plans before visiting remote hot springs.
Is Loftus Hot Spring crowded?
Loftus Hot Spring is accessible from a paved road, making it easy to reach. Weekends and holidays may be busier — consider visiting on a weekday for a quieter experience.
What should I bring to Loftus Hot Spring?
Essentials for Loftus Hot Spring: 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.