A Short High-Altitude Escape: Hiking St. Mary's Glacier and Soaking in Geothermal Caves
A brisk alpine hike to a glacieret, followed by lunch in a Gold Rush town and a restorative soak in geothermal caves.
By the time the van pulls off I‑70 and the highway noise thins, the air tastes like metal and cold—an altitude you feel before you register it. At 10,200 feet the trailhead sits in a bowl of lodgepole pines and scrub, the kind of high-country threshold that promises both immediate reward and an honest exertion. Within an hour of Denver you can be standing beside a deep, alpine lake rimmed with battered ice and snow, the so-called "glacier"—a compact, semi-permanent snowfield that dares you to come closer. Later, after the boots are dry, you slip into the dark warmth of a geothermal cave pool: muscle-soothing heat that feels almost impossible after mountain chill.
Trail Wisdom
Respect the Altitude
Start slow, hydrate before you hike, and watch your pace—even short climbs feel harder above 10,000 ft.
Traction in Winter/Spring
Pack microspikes or waterproof crampons when snow or ice are present; they transform tricky sections into manageable steps.
Timing for Photos
Late afternoon light softens reflections on the lake and reduces harsh shadows on snow; aim for golden hour where possible.
Space for Soak
Bring a small towel and dry clothes for Indian Hot Springs—it's a nicer experience if you change into dry layers right after.
Local Knowledge
Hidden Gems
- •Walk Idaho Springs' historic Main Street for miner-era architecture and small shops
- •Short detour to nearby Guanella Pass for additional alpine viewpoints in summer/fall
Wildlife
Mule Deer, Pika
Conservation Note
This high-alpine environment is fragile—stick to established trails, pack out all trash, and avoid stepping on alpine vegetation to protect soil and plant recovery.
Idaho Springs rose during the Colorado Gold Rush in 1859 and retains historic mining architecture and cultural markers along its Main Street.
Seasonal Guide
spring
Best for: Snowfields and blue-ice edges, Fewer crowds on weekdays
Challenges: Wet, unstable talus, Variable avalanche risk on slopes
Spring still holds significant snow; bring traction and expect slushy approaches and cold runoff.
summer
Best for: Warm weather hiking, Clear views and accessible trailhead
Challenges: Strong sun and sudden storms, Crowded parking on weekends
Summer offers the most predictable trail conditions and the best window for views; plan for sun protection.
fall
Best for: Crisp air and fall color lower on the approach, Fewer visitors
Challenges: Early snow at altitude, Shorter daylight hours
Fall yields cool, clear days and quieter trails; watch the weather as snow can arrive early.
winter
Best for: Snowshoeing and alpine silence, Photographing snow-scoured landscapes
Challenges: Icy conditions and limited parking, Need for traction and winter gear
Winter transforms the valley into a stark white landscape—bring traction, warm layers and expect slower travel.
Photographer's Notes
What to Bring
Sturdy Hiking BootsEssential
Support and traction on talus, tundra and variable trail surfaces.
Microspikes (or Crampons)Essential
Essential for icy or snowy approaches to the glacieret in winter and spring.
Insulating Layer + Wind ShellEssential
Alpine temperatures shift quickly; a windproof, insulating layer keeps you comfortable at the lake.
2L Water Reservoir or BottlesEssential
Hydration is critical at altitude—carry more than you think you'll need.
Common Questions
How long is the hike to St. Mary's Glacier?
The hike to the lake and snowfield is short—about 1–1.5 miles round trip—with roughly 300–500 feet of elevation gain from the trailhead depending on parking.
Is this tour appropriate for beginners?
Yes—this guided tour is beginner-friendly if you're comfortable walking uphill at altitude; guides help pace the group and advise on safety.
Do I need a reservation for Indian Hot Springs?
The tour includes entry to Indian Hot Springs for its scheduled soak; if going independently, check the hot springs' current booking policies for cave pools and soaking times.
What should I wear in winter?
Wear insulated layers, waterproof boots, and bring traction devices—temperatures are cold and wind exposure is higher near the glacieret.
Are dogs allowed on the trail?
Trail regulations can change—check the management rules for St. Mary's Glacier area before bringing pets; tours may restrict animals for safety and logistics.
Is parking available at the trailhead?
Parking is limited and fills quickly on weekends; guided tours typically handle transport to avoid parking issues—arrive early if you plan to self-drive.
What to Pack
Water (2L) for altitude hydration; Microspikes in winter/spring for traction; Layered clothing + wind shell for temperature swings; Sturdy hiking boots for talus and uneven trail.
Did You Know
St. Mary's Glacier is a cirque glacieret—a semi-permanent snowfield rather than a classical flowing glacier—remaining year-round in shaded pockets at high elevation.
Quick Travel Tips
Acclimatize and hydrate before arrival; Arrive early on weekends to beat parking crowds; Bring sunscreen and sunglasses for high-altitude sun; Check traction needs in winter and pack microspikes.
Local Flavor
After the hike, head to Beau Jo's in Idaho Springs for a filling Colorado-style pizza and then wander Main Street for miner-era charm; finish the day with a soak at Indian Hot Springs to recover your legs and trade stories with locals.
Logistics Snapshot
Closest airport: Denver International Airport (DEN). Driving distance: ~45 miles / 40–60 minutes from Denver. Trailhead: St. Mary's Glacier parking area (elevation ~10,200 ft). Cell service: intermittent at trailhead and spotty on the hike. Permits/passes: none required for day hiking, but parking fills fast—guided tours include transport and hot springs entry.
Sustainability Note
This is a fragile alpine area—pack out all waste, keep to established trails, avoid trampling tundra plants, and use biodegradable products before entering hot springs.