Thermopolis | USA Wyoming

Thermopolis is an incorporated town and the seat of Hot Springs County, situated at the northern end of the Wind River Canyon. Known as the "Hot City" (from the Greek thermos and polis), it is defined by its massive geothermal activity, its status as a premier paleontological site, and its history as a medicinal retreat. It serves as a critical tourism hub for North-Central Wyoming.

Historical Timeline

Inhabited by the Shoshone and Arapaho peoples, who referred to the waters as "Smoking Waters" (Bah-gue-wana). A critical historical event occurred in 1896 with the signing of a treaty between the tribes and the U.S. government, selling a 10-mile square piece of the Wind River Reservation. The treaty included a mandate that the "Big Spring" remain free to the public. Founded in 1897, the town grew rapidly as a sanatorium and medical center. In 1993, major dinosaur fossil discoveries nearby transformed the town into a world-class paleontological research center. In 2026, it remains a primary wellness and recreational destination.

Demographics & Population

The 2026 population is approximately 2,750. The demographics are White (93%), Native American (1.5%), and Hispanic or Latino (2.5%). The economy is driven by Tourism, Healthcare (Gottsche Rehabilitation Center), Agriculture, and Energy (oil and gas production in the Grass Creek Field).

Urban Layout & Key Districts

Thermopolis is a compact town situated in a valley surrounded by the Owl Creek Mountains.

Downtown Historic District: The commercial core; features 19th-century storefronts, local art galleries, and independent diners.

Hot Springs State Park District: Located on the north edge of town; the primary recreational zone containing the springs, bathhouses, and the state bison herd.

East Thermopolis: A residential and industrial enclave home to the Wyoming Dinosaur Center and heavy equipment services.

Top City Landmarks

Hot Springs State Park: Wyoming’s first state park; home to the Big Spring, which flows at 13.6 million liters per day at a constant 57°C.

State Bath House: A facility where the public can soak in 40°C mineral water for 20 minutes at no charge, honoring the 1896 treaty.

Wyoming Dinosaur Center: One of the world's top dinosaur museums; features over 30 mounted skeletons (including "Jimbo," a Supersaurus) and active dig sites.

Legend Rock Petroglyph Site: (Located 34 km northwest); a 300-meter sandstone cliff featuring over 280 petroglyphs dating back thousands of years.

The Swinging Bridge: A suspension footbridge over the Bighorn River providing views of the Rainbow Terraces (travertine formations).

Hot Springs County Museum: Home to the original Hole-in-the-Wall Bar, frequented by Butch Cassidy and the Sundance Kid.

Transportation Network

Movement is automotive and pedestrian-centric. Thermopolis is located on US-20 and WYO-789. Public transit is limited. Hot Springs County Municipal Airport (HSG) serves general aviation. There is no passenger rail service; BNSF freight lines run through the Wind River Canyon.

Safety & "Red Zones"

The general safety level is very high. Crime is negligible. Environmental hazards are the primary concern: Scalding water burns (stay on boardwalks in the state park), wildlife encounters (bison in the park), and severe winter road closures in the Wind River Canyon.

Digital & Financial Infrastructure

Internet speeds are moderate to high, with fiber available via local providers like Range. Mobile service is strong in town but unreliable within the deep walls of the Wind River Canyon. Card acceptance is universal. Wyoming has no state income tax. Hot Springs County/Thermopolis levies a 6% total sales tax.

Climate & Air Quality

Temperatures range from -10°C to 2°C in winter and 11°C to 31°C in summer. The valley location offers a slightly more temperate climate than the surrounding high plains. Air quality is pristine.

Culture & Social Norms

The standard tipping percentage is 20%. A "Welcoming-Western" greeting is standard. Dress codes are "Outdoor-Casual" (swimwear is common in the park, but street clothes are required in town). The city is culturally defined by Healing Waters, Paleontology, and Outlaw History.

Local Cost Index

1 Espresso: $4.25 (USD)

1 Standard Lunch: $14.50 (USD)

1 Dinosaur Center Admission: $20.00.

Nearby Day Trips

Wind River Canyon: (Starts 6 km south; a spectacular scenic byway with 700-meter walls and ancient rock layers).

Boysen State Park: (35 km south; a massive reservoir for boating and walleye fishing).

Wyoming Whiskey Distillery: (20 km north in Kirby; the state’s first legal bourbon distillery).

Facts & Legends

Thermopolis claims the "World’s Largest Mineral Hot Spring." Historically, it was a "neutral ground" where various tribes would soak in peace. A local legend involves the "Healing Bison," a specific member of the state herd said to lead sick animals to the warm mineral runoff to recover. Another legend concerns the "Sacajawea Well," an abandoned oil well that blew out in 1918 and now flows as a massive, colorful mineral geyser on the Fountain of Youth resort grounds.