The Grinnell Glacier Trail in Glacier National Park's Many Glacier valley is one of Montana's most rewarding hikes, leading to one of the few remaining accessible glaciers in the contiguous United States. The trail covers 11.2 miles round trip with 1,600 feet of elevation gain, beginning at the Many Glacier Hotel trailhead or—for those using the boat shuttle—at the far dock on Lake Josephine, which shortens the round trip by approximately 3.6 miles.
From the Many Glacier Hotel trailhead, the route travels along the forested shoreline of Swiftcurrent Lake before ascending steadily through open alpine terrain. The trail passes Grinnell Lake—known for its vivid turquoise color produced by glacial flour suspended in the water—before switchbacking up toward the Upper Grinnell Lake basin at approximately 6,400 feet. The final approach to the glacier involves a rocky, eroded section requiring careful footing, particularly when patches of snow or ice linger into August.
At the top, Grinnell Glacier presents a striking scene: a remnant ice field draped against the rocky face of the Continental Divide, with meltwater streams and Grinnell Lake spread below. The glacier has retreated dramatically over the past century, and park service interpretive signs along the route document the extent of historical ice coverage with comparative photographs. Upper Grinnell Lake, formed from glacial meltwater, is a vivid shade of blue-green that intensifies under direct sunlight.
Wildlife encounters are common throughout the hike. The Many Glacier valley hosts one of the highest concentrations of grizzly bears in the lower 48 states. Mountain goats frequent the cliffs above the glacier, and bighorn sheep are often spotted on the scree slopes below. The park entry fee or America the Beautiful Pass is required. Parking at Many Glacier fills by 7 a.m. on summer weekends; arriving before 6:30 a.m. or shuttling from St. Mary is advisable. No trail permit is required for day use. Water is available at the Many Glacier Hotel; stream water along the route requires filtration.
Trail facts
- Trail area
- Many Glacier, Glacier National Park
- Best season
- Late July–September (snow can block trail before late July)
What to bring
- Hiking boots with ankle support
- Bear spray mandatory
- Warm layer
- Trekking poles
- 3L water
Location
Many Glacier Hotel, Many Glacier, MT 59434
48.7962, -113.6572 View on map
Highlights
- Close-up views of Grinnell Glacier—one of the last accessible glaciers in the contiguous United States
- Vivid turquoise waters of Grinnell Lake and Upper Grinnell Lake fed by glacial meltwater
- Optional boat shuttle across Swiftcurrent Lake and Lake Josephine, reducing the round trip by 3.6 miles
- High-density wildlife corridor with frequent grizzly bear, mountain goat, and bighorn sheep sightings
- Interpretive panels documenting a century of glacial retreat with side-by-side historical photographs
Tips for visiting
- Arrive at Many Glacier parking by 6:30 a.m. on summer weekends—the lot fills by 7 a.m.
- Consider taking the boat shuttle ($26/person, 406-257-2426) to reduce the round-trip distance by 3.6 miles
- Carry at least 3 liters of water; stream water along the route requires filtration or treatment
- Bear spray is mandatory in the Many Glacier valley—hike in groups and make noise on blind corners
- Snow can block the upper switchbacks until late July; check current trail conditions on the park website before visiting
- Trekking poles significantly reduce fatigue on the rocky final approach to the glacier
When to visit
Late July through mid-September is optimal, when the upper trail is clear of snow and the glacier is fully visible. Weekday mornings with an arrival before 7 a.m. are advisable to secure parking at Many Glacier.
Accessibility
The Grinnell Glacier Trail is not wheelchair or stroller accessible. The route involves sustained uphill climbing, uneven rocky surfaces, and potentially icy sections near the glacier that are unsuitable for mobility aids.
Frequently asked questions
What is the boat shuttle service on the Grinnell Glacier Trail?
Glacier National Park's concessioner operates a two-stage boat shuttle across Swiftcurrent Lake and Lake Josephine, reducing the round-trip hike by approximately 3.6 miles. Tickets cost around $26 per person; reservations can be made by calling 406-257-2426.
Is the glacier still visible and reachable from the trail?
Yes, Grinnell Glacier is visible and reachable during peak season (late July through September). The ice field has retreated significantly over the past century and is smaller than in historical photographs displayed on park interpretive signs.
Is the Grinnell Glacier Trail safe for solo hikers?
Solo hiking is not recommended in the Many Glacier area due to the very high density of grizzly bears. Hikers should travel in groups of three or more, carry bear spray, and make noise throughout the route.
How early does the upper trail open each season?
The lower sections are accessible from late May, but the upper trail near the glacier is typically snow-covered until late July. The park posts current trail conditions on its website and at the Many Glacier Visitor Center.
Are there restroom facilities along the trail?
Restrooms are available at the Many Glacier Hotel and at the boat dock. There are no facilities along the trail itself.