
• Roystone Hot Springs is a historic site offering an enjoyable soaking and swimming in mineral-rich water
• Features a large warm swimming pool and a small hot pool
Roystone Hot Springs sits in the rural community of Sweet, about 13 miles northeast of Emmett and roughly an hour from Boise. These Central Idaho hot springs blend mineral-rich soaking with a welcoming, family-run atmosphere. It’s easy to plan a mellow day here and pair your soak with nearby outdoor adventures along the Payette River and scenic Highway 55.
The geothermal story goes back to the 1800s, when Native Americans and early settlers used these hot mineral waters for soaking, laundry, and irrigation. Over time, locals built a large cement pool and piped multiple springs into it, creating today’s managed hot springs experience with controlled temperatures and modern amenities.

Roystone Hot Springs Experience
Thermal water at Roystone Hot Springs emerges at about 143°F (62°C) and is cooled for comfort.
The main pool is kept around 98°F (37°C) and feels warm, soft, and inviting for longer swims and kid-friendly fun. The pool is approximately 50 feet long and designed for relaxed laps and play.
For higher heat, the smaller jetted soaking tub holds about 12 people at roughly 104°F (40°C), delivering classic hot springs warmth with bubbles and jets.
The mineral profile is sodium-bicarbonate dominant with a slightly alkaline pH (~7.5). The pools are chlorinated. A clean, light mineral scent is typical.
Swimwear is required in public areas. Facilities include heated changing rooms, showers, a reservable party room, and an event center.
Outside, you’ll find a picnic shelter with tables, a sand volleyball court, a hot spring splash pad for kids, and sports equipment for casual play. You can reserve the entire pool for private events or visit during open swim hours.

Beyond the Hot Springs: Other Adventures
Your visit can be more than soaking. Float, paddle, or fish nearby stretches of the Payette River, bike quiet country roads, or sample seasonal fruit stands and u-pick orchards around Emmett.
Wildlife viewing is common across the surrounding ranchlands and riparian corridors - watch for herons, egrets, raptors, deer, and songbirds along country creeks.
Building an easy day trip is simple: relax at Roystone, then cruise Highway 55 toward Cascade and McCall for mountain views, or explore small-town eats in Emmett and Horseshoe Bend.

Roystone Hot Springs Camping and Lodging
Tent and RV camping are available on-site, with picnic tables and fire pits. The event center and party room can be booked for birthdays, reunions, youth groups, and retreats.
If you prefer more comfort, nearby Emmett and the Boise metro offer a range of hotels and vacation rentals - handy if you plan to tour wineries, orchards, or the Payette River corridor. Many options are within an hour’s drive and offer amenities like pools, hot tubs, and easy highway access.
Roystone Hot Springs | Facts
Location: 13 miles northeast of Emmett • Idaho • USA
Open: Year-round
Development: A large warm swimming pool and a small hot soaking pool with jets and bubblers
Clothing: Required
Amenities: Changing rooms, shower, event center, picnic areas and tables
Accommodations: Tent and RV campground
Hiking distance: Short
Road Access: Any vehicle
Day-use: Yes with fees, reservation is required
Elevation: 2,600 ft (792 m)
Water T° (source): 143°F (62°C)
Water T° (large pool): 98°F (37°C)
Water T° (soaking pool): 104°F (40°C)
Water acidity level: Slightly alkaline (pH=7.5)
Springs Type: Sodium Bicarbonate
Chemical used: Yes, chlorine
| Cations Sodium (Na) - 160 Mg/L Calcium (Ca) - 8.7 Mg/L Potassium (K) - 7.7 Mg/L Magnesium (Mg) - 0.6 Mg/L | Anions Bicarbonate (HCO3) - 187 Mg/L Silica (SiO2) - 120 Mg/L Sulfate (SO4) - 110 Mg/L Chloride (Cl) - 62 Mg/L Fluoride (F) - 16 Mg/L Phosphate (PO4) - 0.4 Mg/L |
More Adventures
Directions to Roystone Hot Springs
From Boise,
- Head northwest on State Street/ID-44 to Highway ID-55
- Turn right onto ID-55 and follow 19.5 miles north to Highway ID-52
- Turn left onto ID-52 and continue 10 miles west to the destination on the right.
Phone: 208-584-3371
Email: kathyjohns10@gmail.com
roystonehotsprings.com








