🇺🇸 USA · Boulder, Montana
♨ Temperature
58°C
⛰ Altitude
1310 m
⚗ pH
—
💧 TDS
—
🌊 Flow rate
—
📅 Established
—
✓ Verified on 2026-07-24
Boulder Hot Springs Inn & Spa occupies a remarkable 1888 mission-revival building in Boulder, Montana, sitting atop geothermal springs that discharge at 58°C. The property has served as a hotel, a boarding school, and a retreat center in its varied history, and today operates as a bed and breakfast with a full geothermal spa. The hot spring water flows into two outdoor pools and a large indoor plunge. The historic architecture and surrounding Jefferson County ranch landscape make it one of Montana's most distinctive thermal destinations.