Located along the Trillium Gap Trail – off the Roaring Fork Motor Nature Trail – Grotto Falls is a nearly 3-mile, out-and-back hike that runs behind a 25-foot waterfall. It's the only ...

Unique for its behind-the-waterfall experience, Grotto Falls is accessible via the 3-mile round trip Trillium Gap Trail. This hike is relatively easy, winding through a lush, old-growth forest.

Rainbow Falls and Grotto Falls. Along the loop, you'll see historic log cabins, gristmills and an array of wildlife, which may include birds, deer and black bears. Stop for a self-guided walking ...