On the Boulder River south of Big Timber, the river drops about 100 feet where it disappears underground into limestone and re-emerges from the cliff face. The original natural rock bridge collapsed in 1988, but the falls remain a short, accessible walk.
Its 100 ft drop is taller than about 74% of the 775 waterfalls we track.
Natural Bridge Falls sits on Boulder River. It lies in Sweet Grass, Montana. The site is on public land managed by U.S. Forest Service (Custer Gallatin National Forest).
This is a roadside waterfall: visible from a road, parking area, or a walk of a few hundred feet. Little to no walking is required, so it suits a quick roadside pull-off rather than a dedicated hike. The walk to the main viewpoint runs about 0.7 miles round trip. The nearest town is McLeod.
When to go: May to September. Water volume swings with the seasons here, strongest after snowmelt or rain and lowest in late summer, so check recent streamflow before you go.
