Riverside Hot Springs Inn & Spa

What to expect

The Riverside Inn is a hotel first and a hot spring second. It is a red-brick building from 1914 on Portneuf Street in the middle of Lava Hot Springs, backing onto the Portneuf River. Today it trades as Riverside Hot Springs Inn & Spa, an adults-only inn with 18 individually decorated rooms, a restaurant and bar, a small morning café and a basement spa.

The soaking is done indoors. On the lower level there are three private soaking rooms, each with its own tub, across the hall from the massage rooms. Hot mineral water reaches the building at up to about 112°F44°C, according to the hotel, and is tempered to somewhere between 102 and 106°F39 and 41°C before it fills the tubs. It runs through continuously and is not chlorinated. Lava Hot Springs water is known for having no sulfur smell, and the inn makes a point of that too.

This is not a place for a long, social soak under the sky. Each booking is a private 30-minute slot, so it suits a couple who want a quiet hot soak before dinner or after a day on the river. If you want big outdoor pools, the state-run hot pools are about a block and a half away on Main Street.

Rooms include the soaking, coffee and tea, a light breakfast at Café A’more (served 7 to 11 a.m.), Wi-Fi and parking. The Portneuf Grille & Lounge on site serves dinner, with a happy hour in the late afternoon. The inn is staffed around the clock.

Getting there

Lava Hot Springs is in southeast Idaho on US Highway 30, between Interstate 15 and Soda Springs.

• From I-15 (Pocatello or Salt Lake City): Take exit 47 at McCammon and head east on US-30 toward Lava Hot Springs and Soda Springs. Follow it 11.2 miles. Take the first exit into town, go two blocks down the hill to Main Street, turn left, and continue about two and a half blocks. The inn’s parking lot is on the left.
• Westbound on US-30 (from Soda Springs or Wyoming): Take the first Lava Hot Springs exit onto Main Street. You pass the state hot pools after about a block and a half. Turn right into the Riverside lot.

Parking is free and on site. The nearest airports are Pocatello and Idaho Falls. Most long-distance visitors fly into Salt Lake City and drive north. The hotel lists Jackson Hole as about 2 hours 45 minutes away and West Yellowstone as about 3 hours 30 minutes.

Prices and booking

There is no separate soaking fee because there is no public access. The tubs are only for registered guests, and soaking is bundled into every room rate. Room prices change by date and room type, so check the hotel’s own booking page. The inn says direct bookings get its package discounts, which include lodging and dining deals and a midweek package for seniors.

How it works once you arrive:

• Check-in is 3 p.m., check-out 11 a.m.
• Register for a soak at the front desk. The three rooms are shared among all guests, so book a time early on busy weekends.
• Each soak is limited to 30 minutes.
• Robes and towels are available at the front desk.
• Massage is by appointment only, at least 24 hours ahead. The spa asks for a card to hold a booking and charges the full price for cancellations inside 72 hours. The hotel suggests a half-hour soak right before your massage.
• Pets: one dog per room, 50 pounds or less, $15 per night plus tax.
• Non-smoking throughout.

What to wear in a private room is up to you. The spa rules do say that soaking is not allowed after drinking alcohol, or for people with untreated high blood pressure or uncontrolled diabetes, and they ask pregnant guests to tell staff before treatments.

The hotel is adults-only. It is not set up for families, and it is not ADA accessible: the building is historic and every room and the spa are reached by stairs.

When to go

The inn is open all year, and an indoor tub works in any weather. That makes it a good winter base. Lava Hot Springs is a busy summer town, with tubing on the Portneuf River and crowds at the state pools, so summer weekends book up and the shared soaking slots go fast. Midweek in the cooler months is calmest.

History

William “Billy” Godfrey, a cattle rancher from Dempsey Creek west of town, built the hotel on the riverbank in 1914 because of the supply of hot mineral water there. The hotel says the early building had large cement tubs for bathers, a café and the offices of the town’s first doctors, and that it served as a makeshift hospital during the 1918 flu pandemic. It picked up the nickname “The Honeymoon Hotel” early on, and the current owners lean into that. The building was listed on the National Register of Historic Places as the Riverside Inn in August 1979.

Where to stay nearby

You are staying here, so the question is really about alternatives if it is full or if you have kids along.

• The Lava Hotel, a short walk west on Main Street, also has a guest-only geothermal pool, plus tiny houses and rental homes.
• Lava Hot Springs has many small motels, inns and vacation rentals within walking distance of the state pools, and campgrounds on the edges of town.
• Pocatello, back west via McCammon and I-15, has chain hotels and full services.

Safety notes

• Heat: 102-106°F39-41°C is hot for a small tub. The 30-minute limit exists partly for hydration. Drink water, and get out early if you feel light-headed.
• Alcohol: The spa does not allow soaking after drinking, even though there is a bar upstairs. Soak first.
• Stairs: Wet feet on the stairs between the spa and rooms are a real slip risk. Wear sandals.
• Health: Check with a doctor before hot soaking if you are pregnant or have heart or blood pressure problems.

Nearby stops worth adding

The state-run hot pools in Lava Hot Springs are the obvious second soak, with outdoor soaking pools kept at a range of temperatures. In summer, tubing the Portneuf River through town is the other big draw. Farther afield, the hotel promotes day trips to Grays Lake National Wildlife Refuge, and Grand Teton and Yellowstone are each a long day’s drive north.