Grinnell Glacier is a 10.6 mi trail with 1,840 ft of climbing — about 4h 25m of moving time before you stop for anything. Dogs are not allowed, and we rate it comfortable from age 12. About 30% of it is shaded, and no refill point is recorded on the route.
Underfoot & overhead big day to a shrinking glacier
10.6 mi and 1,840 ft of climbing work out to 4h 25m of moving time — before you stop for anything. No refill is recorded on the route — you carry all of it. Informational only, not medical advice.
Get the summer refuel plan →NAISMITH · CDC · ACSM · how these numbers are worked out
In July, Glacier National Park runs around 79°F at the main visitor elevation. With no refill recorded on the route, everything you drink starts in your pack.
56°F · Patchy Smoke · wind 5 mph
NOAA forecast for Glacier National Park — not for this trailhead specificallyIn 2026, Two Medicine's North Shore Trailhead is not accessible due to construction in the Two Medicine Campground. A reroute has been established to access the North Shore Trail but does require a ford (unbridged...
Live NPS alert for Glacier National Park · sourceThe Going-to-the-Sun Road is fully open for the 2026 summer season. The road may now be accessed by motorized vehicles over Logan Pass from both the West Glacier and St. Mary Entrances.
Live NPS alert for Glacier National Park · sourceAbout 4h 25m of moving time for 10.6 mi and 1,840 ft of climbing — that is Naismith's planning rule, so it counts walking only, with nothing for photos, lunch or the queue at the top.
Planning figures for that much moving time are 2.2–4.5 L, cool day to hot. No refill point is recorded on the route, so you carry all of it. Informational only, not medical advice.
No — Grinnell Glacier is closed to dogs. Our Glacier National Park dog guide lists the trails where they are welcome, plus boarding and the nearest 24/7 vet.
We rate it comfortable from age 12. It is not a stroller route. That rating is our own hand-check of length, footing and exposure, not an official NPS grade.
About 30% of the route is shaded, and Glacier National Park peaks around 79°F in its hottest month. The less shade a route has, the more of it you want behind you before midday.