If you are in Yellowstone and wanting to see hot springs and nice waterfall all in short day hike, the Mystic Falls hike is a great option. The most direct route to the falls is only a 1.2 mile, 30 minute walk (one-way) on a flat trail...
Bridal Veil Falls Hike
Hidden in a small, easily overlooked side canyon of Clarks Fork Canyon near Clark, WY, Falls Creek plunges 100+ feet at Bridal Veil Falls. It is roughly 2 miles one-way to reach a good vantage point of the falls...