Swimming in Yellowstone offers a rare chance to soak in steaming waters while framed by dramatic canyons and alpine wilderness. Unlike typical resort pools, these geothermal features and alpine lakes demand careful planning and respect for nature.
Below you will find a practical overview of what to expect, how to prepare, and how to explore this iconic park responsibly. The sections that follow cover safety rules, prime swimming locations, and essential tips for a memorable visit.
| Feature | Location | Water Temperature | Access Type | Fee |
|---|---|---|---|---|
| Boiling River | Undara, near Mammoth | 100–110°F (38–43°C) | Natural soaking in designated area | Park entry fee applies |
| Firehole River Swimming Area | Firehole Canyon Drive, Madison Junction | 85–95°F (29–35°C) | Rocks and shallow wading | Park entry fee applies |
| Cody Rapids | Lamar Valley | Cold glacial melt | Natural river swimming in season | Park entry fee applies; trail access |
| Clear Lake | West Entrance corridor | Variable, typically 60–70°F (16–21°C) | Designated swim beach and boat launch | Park entry fee applies; boat required for main area |
| Mountain Lake | Near Tower-Roosevelt | Cold, alpine conditions | Hike-in wilderness swimming | No direct fee; backcountry rules apply |
Stay Safe Around Steaming Water
Thermal Features Require Extreme Caution
Boiling River and other geothermal sites can change rapidly in temperature and chemistry. Never step off marked paths, as thin crusts can conceal boiling mud or acidic water.
Know Your Limits in Hot Springs
Prolonged soaking in very hot water can cause lightheadedness or heat stress. Move slowly, hydrate often, and exit immediately if you feel dizzy or nauseated.
Find Your Swimming Spot
Boiling River at Undara
This natural soaking pool forms where a geothermal creek meets the Gardner River. Expect crowds in peak season and follow posted hours and capacity limits.
Firehole River Warm Sections
Several pullouts along Firehole Canyon Drive offer shallow swimming in warmer stretches. These are not lifeguarded and have uneven rock entries.
High Country Lakes and Rivers
Lakes like Clear Lake and alpine streams in Lamar Valley provide colder, more traditional swimming. Boat access at Clear Lake can save you a long carry if you have the right permits.
Prepare for Mountain Conditions
Weather and Timing Strategies
Summer afternoons can bring thunderstorms, while early mornings tend to be calmer and clearer. Start early to enjoy better light and smaller crowds at popular soak spots.
Gear and Health Essentials
Water shoes protect against sharp rocks and thermal edges, while quick-dry clothing makes cold exits more comfortable. Sunscreen, a wide-brim hat, and electrolyte drinks help you manage altitude and sun exposure.
Wildlife and Etiquette on the Water
Bison, elk, and bears frequent river corridors, so maintain a safe distance and store food properly. Keep voices low near soaking areas to minimize disturbance to others and to better enjoy birdsong and the hiss of steam.
FAQ
Reader questions
Is swimming allowed in all thermal features in Yellowstone?
No. Only designated sites like the Boiling River and a few developed areas along Firehole Canyon are intended for swimming; soaking in hot springs directly from the ground is prohibited to protect visitors and fragile features.
When is the best time of day to visit Boiling River?
Early morning on weekdays is ideal for smaller crowds and softer light. Popular times in summer can fill quickly, so arrive before official opening if permitted and check current conditions at visitor centers.
Do I need a backcountry permit to swim in rivers and lakes?
Park entry covers most day-use swimming, but extended backcountry trips involving camping may require a permit depending on your route, especially when crossing rivers or using designated campsites near waterways.
What should I do if I encounter wildlife near the water?
Stay at least 100 yards from bears and wolves, and 25 yards from other animals. Back away slowly without running, secure food, and follow guidance from rangers to ensure safety for both you and the wildlife.