Short, steep and spectacular: this Denver-based day trip pairs a 1.5-mile alpine hike at St. Mary’s Glacier with a soak in early-1900s geothermal cave pools and a stop for Colorado-style pizza in Idaho Springs.
More ways to explore the area's outdoor wonders
The air thins as the group leaves Denver behind and climbs toward 10,200 feet. Pine scents sharpen, boot crunch meets snow or scree depending on season, and a compact alpine lake opens at the trail’s end — this is St. Mary’s Glacier in Clear Creek County. The trail is short and steep, so breaths come fast and the panorama of jagged ridgelines and mineral-streaked rock rewards every step.
Difficulty
moderate
Duration
6–8 hours
Fitness Level
Should have moderate cardiovascular fitness and comfort on short steep sections at altitude
Wildlife
History
Idaho Springs grew during the 1859 Colorado Gold Rush; the hot springs caves were excavated between 1903 and 1911 to create walk‑in mineral tubs.
Conservation
This is fragile alpine terrain — stay on durable surfaces and marked paths, carry out all trash, and avoid trampling tundra vegetation to protect recovery zones.
Reserve your spot on the Glacier Hiking & Geothermal Cave Pools Tour today and enjoy a trusted, highly rated experience designed to help you make the most of your adventure.
Dress in layers
Temperatures vary quickly between the trailhead and summit — layering keeps you comfortable from parking lot to lake.
Bring a swimsuit and towel
Cave pools are included and bathing suits are optional; have a quick-dry suit and towel for post-soak warmth.
Watch the clock for altitude
Short trail but high elevation — move at your own pace and hydrate to reduce altitude effects.
Grip gear provided
Crampons or snowshoes are supplied when conditions require them; still bring sturdy hiking boots for trail approaches.
Sturdy waterproof hiking boots
Provides ankle support on steep, often wet or icy approaches.
Insulating layers and wind shell
Layering lets you adjust for sun, wind, snow and cold at high elevation.
fall
Crampons or microspikes (if you own them)
Useful on icy steps even though the operator supplies crampons when needed.
winter
Swimsuit and quick‑dry towel
Needed for the geothermal cave pool soak after the hike.