Trinity Hot Springs

What to expect

Trinity Hot Springs is not a drop-in pool. It is a private club. Before anyone in your group can soak, at least one adult has to join the Trinity Club, and every soak is booked ahead in a 2-hour slot. If you are used to paying at the window and walking in, this is the main thing to know before you make the long drive from Boise.

The property sits in the forested hills of the South Fork Boise River country, in a small community called Paradise between Pine and Featherville. It is a mix of old and new: a historic lodge with guest rooms, a few cabins, a four-bedroom house across the road, a campground, and a fenced outdoor soaking pool fed by the hot spring. There is a clubhouse with a lounge and fitness studio, poolside restrooms and showers, picnic areas with barbecues and fire pits, and a riverside beach for members.

The owners lean heavily on the water. They describe the source as rising from about 2.2 miles down through the granite of the Idaho batholith, and say it is the only spring in North America certified by Germany’s Institut Fresenius as “Natürliches Heilwasser” (natural health water). That is the resort’s marketing, not something this page can check. What visitors notice is simpler: clear water with little or no sulfur smell. You can fill a bottle at the pool to drink, and the gift shop sells 5-gallon jugs for taking water home.

The place also runs weekend yoga, massage and bodywork, concerts and group retreats, so some days have a wellness-retreat feel and on others it may be closed for a private event.

The pool

The club describes a single main soaking pool inside a fenced area. It typically runs about 95-108°F35-42°C in summer and drops to about 90-95°F32-35°C in winter, as the cold air pulls heat out of the water. So it is warm rather than hot in January. Current temperatures are posted on the club’s Facebook page.

Guenther’s Chalet, the rental house, has its own geothermal hot tub on the back porch for people staying there.

Getting there

Trinity is about two hours from Boise, and the last stretch is through remote country with limited cell coverage.

• From Boise: Take I-84 east to Mountain Home (exit 95), then US 20 east. At about milepost 127.5, turn north toward Featherville. The road drops to Anderson Ranch Reservoir and follows the South Fork Boise River upstream to Pine.
• From Pine: Continue upriver toward Featherville. The resort is in Paradise, on Grouse Creek Road, between the two towns.

Save directions before you leave Mountain Home. Fuel and services are limited past Pine. In winter, check road conditions on the Anderson Ranch section before you go.

Note that the club’s own “About” page places it on the Middle Fork of the Boise River. Mapping data, and a KIVI television feature, put it between Pine and Featherville on the South Fork side, which matches the driving route.

When to go

Trinity is open all year, though it may close at short notice for maintenance, cleaning or private events.

• Winter hours: Sunday to Thursday 10am to 7pm, Friday and Saturday 10am to 9pm.
• Summer hours: Sunday to Thursday 10am to 9pm, Friday and Saturday 10am to 11pm.
• Quiet hours run from 10pm to 10am for overnight guests.

Summer is warmer in the pool and the campground is open. Winter soaks are cooler but quieter. Weekends and event days are the busiest, so book early or aim for a weekday.

Prices and booking

All prices are from the club’s 2025-2026 pages and can change without notice. The quote you get at booking is final.

Membership

• Trinity Club: $35 per adult per year. Includes your first soak of the year, a free soak on your birthday, and a 10% coupon for lodging, spa services or retail. At least one person in each party must be a member.
• Paradise Club: $55 per adult per month or $605 a year, with family add-ons ($44 per extra adult, $33 per youth, $22 per child per month). Includes unlimited soaking and classes, and after-hours pool time by request.

Soaking (2-hour slots)

• Adults (18+) $15, youth (5-17) $10, children (0-4) $5 with a required swim diaper.
• Punch passes run from 5 soaks for $50 to 100 for $500 and can be shared between members.
• Members book for their guests and are responsible for them.

Lodging (members only, per night, weekday / weekend)

• Lodge rooms: $180 / $195 for two, up to four people. No pets.
• Cabin Rooms 9 and 10: $320 / $340 for two, up to six people.
• Cabin Suite 11: $340 / $355 for two, up to five people.
• Guenther’s Chalet: $400 / $450, up to 15 people, usually a two-night minimum.

Camping (seasonal, members only)

• Tent site $30, car camping $40, small RV (under 26 feet) $60, larger RV $80, each for one adult. Extra adults are $20 and kids $15.

Lodging and camping guests can use the pool around the clock during their stay.

Spa: Massage and bodywork cost $120 for 60 minutes or $160 for 90 minutes.

To book, call 208-653-2123 (weekdays 10am to 8pm, weekends 10am to 9pm) or email the reservations office. Everyone on site must sign a waiver. The club does not publish a dress code online, so ask when you book if you are unsure.

History

The property has had several names. It was Price’s Plunge, then Paradise Lodge, then Paradise Hot Springs. The Rock family bought it in 2014, and their daughter, Dana Stream, is developing it as a members’ health club and retreat. The family lives on site.

Where to stay nearby

The simplest option is to stay at Trinity itself, which gets you 24-hour pool access. Otherwise, Featherville and Pine have small lodges, cabins and basic services, and the Boise National Forest around them has Forest Service campgrounds along the South Fork. Mountain Home has the nearest chain motels and full supplies.

Safety notes

• Remote roads: The route past Anderson Ranch Reservoir is long and winding, with long gaps between services. Fill your tank in Mountain Home.
• Hot water: Even at 105°F41°C or so, long soaks dehydrate you. Drink water and take breaks.
• Children: Kids are welcome with youth and child pricing, but they need constant supervision around the pool.
• Pets: Keep dogs out of the pool area and leashed elsewhere on the grounds.

Nearby stops worth adding

If you want a free, Forest Service pool on the same trip, Baumgartner Hot Springs is about 11 miles east of Featherville in a summer campground. Anderson Ranch Reservoir, on the drive in, is popular for fishing and boating in summer.