Lava Hot Springs

The public hot pools at Lava Hot Springs in winter.

LAVA HOT SPRINGS – It’s that time of year when the weather goes cold and thoughts turn to one of the most popular of this area’s day trips: visiting some hot springs.

Of course, Lava Hot Springs comes immediately to mind. Just an hour south of Blackfoot, it’s the closest large capacity hot springs open to the pubic year-round. It is also one of the few hot springs which doesn’t reek of hydrogen sulfide, which is that infamous rotten egg smell.


Once part of the Fort Hall Reservation, the United States bought the 178 acres of Lava Hot Springs from the Shoshone-Bannock Tribes in the late 1890s. The land was deeded to the State of Idaho in 1902 for public use.

The Lava Hot Springs Foundation was set up at that time to manage those lands and operate the hot springs. The Foundation is now under the Idaho Department of Parks and Recreation. The history of the hot springs can be read online at

The public pools and buildings at the hot springs have changed greatly over the years, including more than four different generations of changing rooms. There was once even an indoor swimming pool where the hottest of the soaking is not located.

Floods along the Portneuf River in 1962 did large-scale damage to the hot springs and the local town. The rebuilding of the public hot pools and facilities after that flood created the two largest soaking pools recognizable today. The new changing rooms were added to the current building and finished just before 2000. The old changing rooms along the river were torn down at the same time and replaced newest of the soaking pools.

The facility is family-oriented and has some modesty rules (no thongs, G-strings, or cheeksters). There are also rules prohibiting unsupervised children, running, roughhousing, splashing and diving.

As a frequent hot pools visitor, I find that the best times to go for a quiet soak are in the morning when they first open, weekdays during the day Monday through Thursday when school is in session, and during the lunch and dinner hours.

Use doubled zip-lock bags or a waterproof case for your tablet or phone if you want to read or game.

For years, there were webcams mounted on the northwest corner of the changing room building. I used to check them on the hot pools webpage before I left town for a soak to see how busy the pools were.

The east-facing webcam went down a year and half ago and the west-facing one went down about a year ago. Neither has been replaced. If you’re like me and liked the webcam webpage, tell them at the front desk that they should bring them back.


The square easternmost pool has a temperature of 112 next to the Sunken Gardens to 110 next to the changing rooms. The large middle pool with the curved sides has a temperature of 106-108, where the side closest to the river is cooler. These are the oldest pools and they both have gravel bottoms.

About five years ago, the middle pool acquired new sitting benches set at shallow and chair-level heights along the eastern edge next to the changing rooms. The shallow height is perfect for lying down and reading a book or water-proofed tablet while soaking one’s back. Bring an inflatable pillow if you don’t want to get your ears immersed.

Next to the middle pool are the two small whirlpools with jetted-water vents placed at varying heights along a built-in seat-height sunken bench. Both are entered by railed steps. These two pools are at 106 to 105 and have hard-paved floors.

The newest pool was opened about 10 years ago and is next to the river. The floor is paved with smooth natural flagstones. The sides of the pool are lined with two levels of built-in sitting benches. The water temperature is 105 next to the ramp and 102 next to the drain.

The three large pools all have wheelchair ramps. The ramps into the middle and eastern pools are older with a steep side; the ramp into the pool next to the river is gradual and it is the only large pool with a solid floor. There is a water-accessible wheelchair that patrons can borrow; inquire at the front counter when you first enter the facility if you want to use it.

Rates at the hot pools are still under $10 for all ages. Prices vary by age, weekday or weekend, and by individual, family or group. Check the rates at before you go.

The public hot springs are one of the few that still rent swim suits and towels. Suits are $1.50 plus a $5 deposit and towels are $1.50 plus a $5 deposit. Deposits are refundable when the rentals are returned in the gift shop. Small lockers are $0.50; large ones are $1. Bring quarters or use the change machine next to the outside lockers next to the gift shop.


According to the research of Dr. Dick Smith, a retired Idaho National Laboratory geologist, the source of heat at Lava Hot Springs can be attributed to the young volcanic activity and high heat flow from the upwelling mantle plume underneath Yellowstone. That plume is the source of the explosive volcanism and famous geysers at the National Park.

It is also responsible for the lava flows and cinder cones of both the eastern Snake River Plain and the Blackfoot Volcanic Field (BVF) which stretches from Grace to the Blackfoot Reservoir. Activity in the BVF began around a million years ago according to radiometric age dates and ended only recently. Professor Emeritus Mike McCurry of Idaho State University has estimated the ages of youngest basalts in the BVF at approximately 27,000 years old, which is very young in terms of geologic time. The closest of those lava flows is just to the east of Lava Hot Springs, in the valley just on the other side of Fish Creek Pass.

If you go to Lava Hot Springs during daylight hours, consider making a half-hour detour before you head home to visit Niter Ice Cave, which is in one of the Blackfoot Volcanic Field flows dated at approximately 500,000 years old. This is a lava tube just three miles south of Grace with a walk-in packed-dirt ramp and railing into the cave.

Before Grace had electricity, the locals used it during warm weather to store their milk and butter because it stays cool year-round. I’ve seen snow and ice in Niter Ice Cave in August.

The cave is one of the friendliest lava tubes anywhere, easy to enter even for those with aging knees because of the path and rail. Be forewarned that wet weather and dripping water in the spring and fall can make the path very slippery.


Take I-15 south to exit 47. At the top of the off-ramp, turn left to go east on U.S. Highway 30. Drive 14.7 miles and take your second to enter the town of Lava Hot Springs onto Main Street. It may look like you’re about to actually pass the town before you get to this turn. You will be able to look down and see into the hot pools before you get to the turn. The right turn onto Main is just before a little restaurant called Riverwalk Cafe, which has great authentic Thai food for reasonable prices.

Once you take that right turn, you’ll curve around to the right almost 180 degrees past Riverwalk and the laundromat and cabins at the RV Park. After a very short drive downhill past a city park on the left, park on the street to the right or in the parking lot on the left next to the motel. Both are free public parking for the purpose of visiting the hot pools, whose entrance is on the right before the bridge over the river.

To get to Niter Ice Cave, drive east from Lava Hot Springs on U.S. Highway 30 going east toward Soda Springs. After 15 miles, take a right to go eight miles south on Highway 34 towards Grace.

Grace is five miles down Highway 34 and the turn-off to the cave is three miles further. Turn left onto Ice Cave Road. There will be a dirt parking lot on the left after 0.3 miles. The entrance to the cave is just to the east of the parking area. Bring a flashlight if you want to walk all the way in.