From the Fern Lake Trailhead, begin along the relatively flat trail paralleling the Big Thompson River. The canyon through which this trail runs is stunning - the northern wall rises abruptly over 1,000 feet above the valley floor.
Just under two miles from the trailhead, the Fern Lake Trail crosses the river and is met by the Moraine Park Cub Lake Trail
from the south. Near this intersection there is a bridge over the Big Thompson River that is not far from the Arch Rocks or Old Forest Inn campgrounds. The bridge provides a beautiful look at the Big Thompson River as it passes over a small waterfall and under this bridge, coursing out into the meadow in Moraine Park. Enjoy the view down the river!
From here, the gradual meandering character of the trail is now replaced by steepening grades as it heads up the Fern Creek Drainage.
After an initial contouring ascent, the trail begins a series of switchbacks as the terrain steepens. After two large switchbacks the Fern Creek Falls, which you've surely been hearing, will come into view. Take a moment, or many moments, to enjoy the sheer power of the cascades before running up the final portion of trail to Fern Lake.