Gunsight Lake

Overview

Gunsight Lake sits in a dramatic glacial basin beneath Mount Jackson and Gunsight Mountain, with views toward Jackson and Blackfoot Glaciers. The water shifts from clear to a vivid glacial aqua depending on melt and recent weather. It’s a big, rewarding day for strong hikers and a stellar first-night camp on the classic Gunsight–Sperry traverse.

The Hike In (day hike stats)

• Start at Jackson Glacier Overlook on Going-to-the-Sun Road. The out-and-back to the lake is roughly 12.6–13.8 miles with about 1,500–1,900 feet of gain. The first mile trends downhill—remember you’ll pay it back late in the day.
• Early highlights include Reynolds Creek and Deadwood Falls, a long suspension bridge, willow flats along the St. Mary River, and a highly recommended side trip to Florence Falls before the final approach to the lake.
• Expect big scenery to open up near the lake, with classic U-shaped valleys, hanging waterfalls, and skyline glaciers.

Wildlife

The valley is known for moose in the willow flats, with mountain goats often seen higher up toward Gunsight Pass. You’re in both grizzly and black bear country—hike in groups, make noise in brushy stretches, and carry bear spray.

Facilities and Trail Conditions

• No restrooms or water at Jackson Glacier Overlook. Use facilities at nearby east-side stops before you start.
• Along the trail, there are pit/vault toilets at Reynolds Creek and at the Gunsight Lake backcountry campground. Water must be filtered.
• Common on-trail notes: brushy sections (long pants help), mud after rain, and notable mosquitoes/biting flies in season.

Camping and Permits

Gunsight Lake has a designated backcountry campground with food prep/hanging setups and a pit toilet. Backcountry permits are required; some sites release in advance while others are walk-up. Store food properly and keep a clean camp.

Going Farther

From the lake, strong hikers can climb to windswept Gunsight Pass for a dramatic look toward Lake Ellen Wilson. Multi-day parties often continue the traverse over Lincoln Pass to Sperry and down to Lake McDonald, using the park shuttle to connect trailheads.

Best Time to Visit

Mid-July through September is the reliable season. Early July can still hold perilous snow on the pass, and late September can bring fresh snow. Seasonal bridges are typically installed during peak season—verify current trail and bridge status with rangers. Start early for cooler temps, calmer winds, and better wildlife viewing.

Is It Worth It?

Yes—if you’re up for the mileage. Compared to the park’s marquee day hikes, this one feels a touch quieter, and the lake’s color plus the glacier views make the effort pay off.