Seymour Mountain sits at 4,055 feet in the Seward Mountain Range of the High Peaks Wilderness, separated from its three range companions (Seward, Donaldson, and Emmons) by a wide valley, which is why it is almost always climbed on its own rather than in a single push with the other Sewards. There is no maintained trail; the route follows a herd path throughout, making navigation and route-finding skills important.
The approach from the Corey's Road Trailhead is long and gradual, covering roughly five miles to the Ward Brook Lean-To, which many hikers use as a base camp to spread the Seward Range peaks over two days. From the lean-to, about 500 feet down the trail a rock cairn marks the start of the herd path beside a brook; follow the brook southwesterly for roughly half a mile to an old slide. The slide section is steep and heavily eroded, with loose footing that demands care on both ascent and descent. Views open to the north as you climb. When the slide becomes too steep to continue, the herd path re-enters the woods on the right and soon reaches a fork: the right branch leads 50 feet to a rock ledge with views of Upper Saranac Lake and the surrounding ranges, while the left continues 100 feet to the wooded summit.
Route details and trailhead directions are available here. Snowshoes and traction devices are typically necessary in winter, and the steep slide section becomes particularly hazardous when icy.
