The Springs

What to expect

The Springs is the developed choice for a hot soak near Boise. It sits on Highway 21 a mile short of Idaho City, the old gold-rush town in the mountains northeast of the capital, and it is set up like a small modern day spa rather than a rustic plunge. Water from a natural hot spring feeds a large outdoor geothermal pool, roughly 40 by 80 feet, with a separate hot tub beside it. A guide that reviewed the 2013 reopening put the hot tub at about 104°F40°C. The resort says it adjusts the main pool temperature to suit the weather outside, so it runs warmer in winter.

Pine-covered hills surround the deck, and on a winter day you get the classic contrast of snow on the ground and steam off the water. The water itself is clear and quite alkaline (a pH of 9.6 has been reported).

It is a busy, sociable place. Sessions are capped at roughly 65 to 70 people, so it rarely feels packed, but you will not have it to yourself. Live music plays on Monday and Thursday afternoons from 4:30pm to 7pm, weather permitting in the colder months.

The pools

• Main geothermal pool: The big outdoor pool most people come for. Temperature is set by staff according to the season.
• Hot tub: Smaller and hotter, next to the main pool.
• Private tubs: Four tubs rented by the hour for up to four adults. Each has its own cold-water supply so you can set the temperature yourself, and a server can bring food and drinks while you soak. They are 18+ and clothing optional.
• Steam room: Usually 110-120°F43-49°C, for adults only. In fall 2026 the resort listed it as temporarily closed for improvement work.

A portable ADA lift chair (300 lb limit) is available on request for the main pools.

Getting there

The Springs is at 3742 Highway 21, Idaho City, about 45 minutes from Boise.

• From Boise: Head east and then north on Highway 21, the Ponderosa Pine Scenic Byway, past Lucky Peak and up the Mores Creek canyon. The resort sign is on the left just past mile marker 37. If you reach Idaho City, you have gone about a mile too far.
• Road work: Highway 21 has construction at the Mores Creek Bridge (the High Bridge) between Boise and Idaho City that is expected to run into 2027. The resort warns of delays of 15 to 20 minutes during work hours, so leave a buffer before your session starts.

The highway is paved and kept open in winter, but it climbs and curves, and snow and ice are common from November to March. Parking is on site. Plan to arrive about 15 minutes early to check in, especially for a private tub booking.

When to go

The resort is open all year on its current schedule: Thursday through Monday, 10:30am to 10pm, closed Tuesday and Wednesday.

Who can come depends on the day:

• Monday, Thursday, Friday: Adults only (18+) all day.
• Saturday and Sunday: All ages from 10:30am to 7pm, then adults only from 7:30pm to 10pm.

Winter is the most popular season, and weekend sessions sell out first. If you want a quieter soak, book an adults-only weekday in the evening. Families have only the weekend daytime window, so book early.

Prices and booking

Every visit is by reservation, made online or by calling 208-392-9500. The main pool and the private tubs need separate reservations. Prices below are from the resort’s 2026 rate page.

• General soak (2.5 hours, pool and hot tub): $30 adults, $27 children 12 and under.
• Private tubs (18+): $70 plus tax per hour for up to two adults, plus $5 for each extra adult, to a maximum of four. Book one adult online and add the rest at check-in.
• Inn The Pines guests: $25 adults, $22 children, with a guaranteed spot in a general session. Reserve the soak when you book the room.
• Massage: 60-minute table massage, limited availability.

Cards are not charged when you book. If you do not cancel at least 12 hours before your slot, you pay the full price.

House rules worth knowing before you arrive:

• Towels are not provided. Bring your own or buy one at the front desk.
• Lockers are limited and bags are not allowed poolside (private tub guests can bring a mesh or clear bag).
• No outside food or drinks. There is a food and drink menu, with beer and wine served poolside.
• No outside alcohol anywhere on the property, including the parking lot. Staff will refuse service to anyone who looks intoxicated.
• Swimwear: The resort does not publish a dress code for the main pool, but it is a shared family pool, so plan on a swimsuit there. Only the private tubs are described as clothing optional.
• Free cold drinking water is at poolside stations. Bring a refillable bottle.

History

People have soaked here since the late 1800s. Under its old name, Warm Springs Resort, the site has also served as a post office, police station, saloon and stage stop. After years of heavy use it was rebuilt and reopened on February 14, 2013, following about $2.7 million in upgrades and new construction.

Where to stay nearby

The resort runs Inn The Pines, a seven-room hotel just down the highway at 3764 Highway 21. Rooms have WiFi, a fridge and a coffee maker. Hotel guests get the discounted soak rate and guaranteed entry to a session, which matters on sold-out weekends. Cancelling one reservation does not cancel the other, so cancel both if your plans change.

Idaho City itself, a mile up the road, has a handful of other small lodgings, cafes and saloons in its historic downtown. Boise, 45 minutes back down Highway 21, has the full range of hotels. The Boise National Forest around Idaho City has Forest Service campgrounds along Highway 21 for summer camping.

Safety notes

• Hot water: The hot tub and steam room are hot. Keep soaks short, drink water, and get out if you feel lightheaded.
• Children: There are no lifeguards. An adult must supervise kids at all times.
• Winter driving: Highway 21 can be icy, and the road work at the High Bridge adds delays. Carry chains or have good winter tires, and allow time so you are not rushing on the curves.
• Fire season: In fall 2026 a Boise National Forest order (0402-03-140) closes several forest roads (316, 321 and 321A) and trails in the Idaho City Ranger District because of the Crooked Fire, through December 31, 2026. It does not name the highway or the resort. If you plan a drive or hike in the forest around town, check the forest alerts page first.

Nearby stops worth adding

Spend an hour walking around Idaho City. The old gold-rush town has boardwalks, historic buildings and a pioneer cemetery, a short drive from the pool. If you want a wild soak instead, Highway 21 continues north toward Lowman, where several Boise National Forest springs line the road.