This appears to be
Pine Ridge Falls, not
Sill Branch Falls, like I first thought. Both are in Unicoi County, but are very close to Washington & Greene Counties. There are also some nice cataracts to see on the way. These falls can be found down a gravel road and then a short 1/2 mile hike.
Directions: Drive to Clarks Creek Road from state road 107, located 4.9 miles west of state road 81, going toward Greeneville. Clarks Creek Road is also 15 miles east of U.S. 321, coming from Greeneville. Drive 1.5 miles south on Clarks Creek Road. The road turns to gravel and you will drive another 1.6 miles. Here the road crosses the creek a third time and then, after another 0.4 miles, a large unsigned turnout serves as the parking area for the trail.
The trail is a little rocky, but bear left at all junctions. After 0.4 miles you will cross the south fork of Sill Branch and then hike another 0.1 miles to the end of the path at the falls. If you get confused the falls are fairly loud. A few cataracts are loud, but don't mistake them for Sill Branch Falls.