Isn't this bridge part of the Retreat trails system? I believe Retreat patients built the stone tower, higher up, stone steps where needed, and several of these stone landscape features.
Cold Spring (1845)
This spring is located just west of Upper Dummerston Road where it joins Route 30. A source of pure water, it was the destination of daily walks by patrons of Dr. Wesselhoeft's Hydropathic Institution, located in Brattleboro. In 1899 the Retreat built a stone hood over the spring and a rustic bridge of boulders over the ravine. It became a favorite resting place for Retreat patients on their daily walks.