Flattop Mountain Trail

Flattop Mountain Trail is a 12-mile, one-way backcountry route from Packer's Roost to Fifty Mountain Campground, passing Flattop Mountain Campground. It follows the McDonald Creek valley to Mineral Creek, climbs north toward Flattop Creek, then continues over high country to Fifty Mountain. It is a point-to-point backpacking leg with no road at the far end, so plan an onward route or a return over the same trail.

A useful split is 5.7 miles to Flattop Camp and 6.3 more to Fifty. The two backcountry camps have three and five sites respectively. Any overnight in Glacier's backcountry requires a wilderness use permit, so make these stops part of your permitted itinerary. The 12 miles are one way, not a return total.

From Packer's Roost, the trail follows the McDonald Creek valley toward a crossing at Mineral Creek. The valley approach starts relatively level; after the creek, the trail turns north and climbs more steeply on switchbacks toward Flattop Creek. This is the main effort of the route, so give the first half time rather than assuming the climb ends at the first campground.

The high ground is a broad plateau rather than a pointed summit with one obvious viewpoint. Think of this as a long crossing through open alpine terrain, not a quick summit walk. Parts of the upper route pass through fire-scarred pines, with openings toward the surrounding ridges; the exact fire attribution is unsettled, so there is no reason to pin it to a named burn.

After Flattop Campground, another 6.3 miles reaches Fifty Mountain Campground. The route continues across the high plateau and through open patches of forest before arriving at a remote alpine meadow with rugged peaks around it. Fifty Mountain is a remote destination reached on foot as part of a longer itinerary.