This cache is located near the Fall River Campground just south of the Yellowstone Park Boundary. About 1 mile up the river is Cave falls, and a trailhead that connects to the famous Cascade Corner of Yellowstone National Park. There are many waterfalls (over 100!) in the Fall River Watershed, many of which are accessed off trail. If you are looking for a relatively short, family friendly hike that takes around 1-2 hours, then take the trail up about a mile to Bechler Falls.
Note: There is a fee for camping and day use if you plan on staying in the campground. Read the signs nearby for information.