Lonesome Lake is far from lonesome in the peak of summer, especially due to the popular Lonesome Lake A.M.C Hut on its shores, but it still offers a nice respite from the huge crowds found on the valley floor of Franconia Notch State Park. During the shoulder seasons the lake lives up to its name, providing a serene setting to enjoy some great views of the surrounding White Mountains. The route along the Basin Cascade and Cascade Brook Trails is 2.3 miles long. It's slightly longer and more rugged than the Lonesome Lake Trail, but it also has better views and multiple spectacular waterfalls, including Kinsman Falls.
To follow the Basin Cascade Trail, first park at the Basin Trailhead, stopping to enjoy the swirling currents at this iconic falls. A wooden sign marks the trail. The trail veers away from Cascade Brook but returns at the base of some incredible granite slides. The trail parallels these for a short while before cutting away from the river once more and returning at Kinsman Falls. Trail use slackens significantly beyond this point with a stream crossing a short ways above the falls.
The trail continues paralleling the aptly named Cascade Brook for another half mile, where it reaches Rocky Glen Falls. Rocky Glen Falls cascades roughly 40 feet in three tiers. It's a great place to pause for a snack or to cool your feet.
Just up the trail, the Basin Cascade Trail intersects with the Cascade Brook Trail on the southwest shore of Cascade Brook. Cascade Brook Trail is marked with the white blazes of the Appalachian Trail, and it continues across Cascade Brook to Lonesome Lake in 1.3 miles. After the stream crossing the trail slowly bends away from Cascade Brook and begins climbing roughly over boulders and through muddy patches. In most places plank bridges navigate the worst parts.
When the lake comes into view, it's a short walk over a bridge to the Lonesome Lake Hut, or an approximately 0.8-mile loop around the lake. Visitors will find excellent views of Mount Lafayette, especially from the west side of the lake.