Roystone Hot Springs

What to expect

Roystone Hot Springs is a small family operation in the Sweet valley, in the hills between Emmett and Horseshoe Bend. It is set up more like a private swim club than a public plunge. You do not buy a ticket and join a crowd. You book a time slot, and your group gets the pool, or the hot tub, to itself.

The main pool is about 50 feet long, outdoors under a high vaulted roof with open sides and a privacy fence. Hot spring water comes out of the ground at roughly 140-143°F60-62°C, so it has to be cooled. The pool is held near 93°F34°C in summer and 98°F37°C in winter, warm enough for a long swim but not a hot soak. There is a water basketball hoop, a waterfall massage pole, Bluetooth speakers, wide stairs with handrails and a shallow end for small kids. No diving.

The jetted hot tub is the hot option, at about 104°F40°C. It seats up to 12 and has its own patio, dressing rooms and showers. In the evening you can rent a projector and watch a movie on an outdoor screen while you soak, though it only works properly after dark.

The water is chlorinated regularly. Around the pools are lawns, a pickleball and basketball court, volleyball, a hot springs splash pad, lit picnic shelters, fire pits and a Dutch oven cooking area. Much of the trade is family reunions, birthday parties and weddings, and there is a heated party room and a newer event center, the Spring House.

Getting there

Roystone sits at milepost 44 on Idaho Highway 52, halfway between Emmett and Horseshoe Bend. The posted address is 7882 N. Highway 52, Sweet, ID 83670.

• From Boise and the Treasure Valley: Either head to Emmett and continue northeast on Highway 52, or take Highway 55 north to Horseshoe Bend and turn west on Highway 52. The operators describe it as about 45 minutes from most of the valley.
• GPS warning: The owners say phone navigation is unreliable in these hills. Look for the milepost and call 208-584-3371 if you get turned around.

The highway is paved all the way and parking is on site. When you arrive for a swim, call or text the office before going through the pool gate. If you cannot get through, walk to the office east of the pool and ring the bell.

Prices and booking

Everything is by reservation. Booking runs through FareHarbor, linked from the website, or by phone. Rates listed on the booking page in October 2026:

• Private pool session: 1.5 hours, $53 on weekdays or $85 on weekends and holidays, covering up to 10 people.
• Private hot tub (no pool): $25-$53 for the first two people, in 1-hour or 1.5-hour sessions. Ages 8 and up only. You can add the hot tub to a pool session at a discounted flat rate for the whole group.
• Party room: $32-$53 per session, timed to match pool and hot tub sessions.
• Grounds for day use: $25 per hour.
• RV site: $40 per night plus tax, including four people and one pet. Extra people or pets are $3 per day. Pool and hot tub are not included.
• The Guest House: $300 per night for up to eight people.
• Group tent camping: $175 for up to 25 people, plus $3 for each extra person.

Cancellations need 48 hours notice or you pay the base price of each item. Lightning does not earn a refund, so check the forecast and cancel in time if storms are likely. A parent must fill out a one-time waiver for themselves and their children.

Rules and etiquette

Roystone calls itself a family-oriented, alcohol-free facility, and the rules are long and specific. The ones that matter most:

• No alcohol anywhere on the property, except inside the Spring House and its lawn during a private event. No drugs, fighting or lewd behavior.
• Swimsuits. It is a family pool, and the hot tub rules ban public displays of affection outright.
• Supervision: an adult must be inside the pool and hot tub gates with anyone under 18. Children who are not toilet trained need swim diapers, which the office sells for $1.
• Hot tub limits: no pregnant women and no children 8 or younger.
• Inside the pool and hot tub gates: no food, glass, smoking or pets.
• Groups of 35 or more swimmers must hire a licensed lifeguard, a state requirement.
• Quiet hours run 10 p.m. to 8 a.m. Day visitors must be gone between 10:30 p.m. and 8 a.m.
• Fines apply for hanging on the basketball hoop or waterfall pole, and $200 for glitter, confetti, silly string, sparklers, rice and similar mess.

When to go

The pool and RV park are open year-round. Winter is the nicest time for the pool itself, when it is held at its warmest (about 98°F37°C) and steam rises off the water under the roof. In summer the pool is cooled to the low 90s, which feels more like a warm swimming pool. Weekends are pricier and book up with parties, especially in summer, so midweek is easier. The site has a mosquito abatement page, which tells you bugs can be an issue in warm months.

History

People used these springs well before the resort. Settlers, laundry workers and Native people from nearby fishing camps used the water in the 1800s, and the warm flow was later used on farmland and channeled into a concrete basin that became the start of the present pool. Roy Stone bought the springs but died in Portland before moving here. His widow, Eva, named the place after him and ran it as a sanitarium. After two fires and several owners, the Johns family bought the run-down property in the early 1980s and rebuilt the pool and main house. They still run it.

Where to stay nearby

• On site: the RV park (10 full-hookup sites), the Guest House for up to eight, and group tent camping. Tap water on the property is hot springs water with heavy minerals, so bring drinking water.
• Montour Campground, close by in the Sweet valley, is where Roystone sends people who want a single tent site.
• Emmett has motels and services. Boise has the widest choice of hotels.

Safety notes

• Hot tub heat: 104°F40°C is hot. Keep soaks short, drink water and get out if you feel dizzy.
• Lightning: if you see lightning or hear thunder within 30 seconds of the flash, get out of the water and into a building or car. Wait 30 minutes after the last thunder before going back in.
• Children: watch kids around the pool at all times. There is no lifeguard unless you hire one.
• Drinking water: bring your own. The property’s water is mineral-heavy spring water.