A large southeast-facing rockshelter, Twin Branch measures 60 feet long and has a maximum depth of 50 feet. Its maximum height at the entrance reaches approximately 15 feet above the dripline. Toward the back of the shelter, however, the roof is less than 3 feet high.
Roof fall covers most of the floor, especially toward the rear. Although this limits the shelter's available livable space, an ample flat area in excess of 300 square feet would have been available to the site's Fort Ancient inhabitants.
Archaeologists conducted limited excavations at this site in 2006.