Star Plunge is a classic, family-friendly hot springs water park and aquatic center in Thermopolis, Wyoming, just steps from the famous mineral terraces in Hot Springs State Park. For generations, this unique spot has attracted families, road trippers, and adventure-seekers with its mix of natural hot spring pools, thrilling water slides, sun decks, and vapor caves. If you're searching for the best hot springs in Wyoming, it's hard to beat the Star Plunge experience.

You'll spot Star Plunge by its large, bright building nestled among the hills, with steam rising from both its indoor and outdoor pools. The area is full of other hot springs and various outdoor adventures.

The Star Plunge Hot Springs Experience

Star Plunge pools are filled with natural mineral water heated by geothermal energy from deep within the earth. The source water emerges at 127°F and is cooled to comfortable temperatures for soaking and swimming. The indoor pool maintains a temperature between 94°F and 98°F, while the outdoor pool ranges from 90°F to 94°F. The hot pool reaches a relaxing 104°F, and the air in the vapor cave typically hovers around 110°F.

No chemicals are added, just pure, mineral-rich water. The feeling is silky, with a slight "hot springs" scent. Over 27 minerals are naturally present in the healing water.

Star Plunge features two large mineral pools (one indoor and one outdoor), two hot tubs, and two baby pools, all filled with naturally heated, chemical-free mineral water.

You'll also find three exciting water slides: the Super Star 500, Blue Thunder Run, and Lil' Dipper.

The Star Plunge also has a relaxing vapor cave and a complete fitness center.

After swimming, you can unwind on one of ten sun decks overlooking the beautiful Hot Springs State Park.

Swimsuits are required. Please bring your towel and sandals, or you can rent them from the front desk.

Star Plunge is inside Hot Springs State Park, so you’re close to even more adventures:

Walk the terraces: The park’s boardwalks wind through rainbow-colored mineral formations.

Bison viewing: Watch the park’s bison herd roam the hills.

Swinging Bridge: Cross over the Bighorn River for amazing views.

Wyoming Dinosaur Center: Just minutes away, perfect for families.

Legend Rock Petroglyphs: See ancient rock carvings a short drive away.

Wind River Canyon Scenic Byway: Famous for dramatic canyon scenery and wildlife.

Looking for more mineral soaking? Check out Hellie’s TePee Pools, State Bath House, or Fountain of Youth RV Park, all within a short drive.

Location: Thermopolis • Hot Springs County • Wyoming • USA
Open: Year-round
Development: Indoor/outdoor mineral pools, hot tubs, water slides, vapor cave, fitness center, sun decks
Clothing: Mandatory
Amenities & Services: Rentals (towels, suits, tubes), lockers, snack bar (when open), shaded and sunny areas

Hiking distance: Short
Road access: Any vehicle
Day-use fees: Yes

Elevation: 4,331 ft (1,320 m)

Water T° (source): 127°F (53°C)
Water T° (pools): 90°F–104°F (32°C–40°C)
Odor: Sulfur scent
Chemical used: None

Water acidity level: Mild alkaline (approx. pH = 8.0)

Mineral content includes:

Sulfur: High
Calcium: Moderate
Magnesium: Moderate
Sodium: Moderate
Potassium: Present
Chloride: Present
Silica: Present
Iron: Present