🇺🇸 USA · Yellowstone National Park, Wyoming
♨ Temperature
27°C
⛰ Altitude
2133 m
⚗ pH
—
💧 TDS
—
🌊 Flow rate
—
📅 Established
—
✓ Verified on 2026-07-24
The Firehole Swimming Area is one of the few places in Yellowstone National Park where visitors are permitted to swim in geothermally warmed waters. Hot spring runoff from the surrounding geyser basins raises the river temperature to a comfortable 18–27°C during summer. The canyon walls create a sheltered environment, and the clear, fast-moving water provides a memorable swim surrounded by Yellowstone's iconic geothermal landscape. Swimming is only allowed from late June through early September when water levels and temperatures are safe.