Tri-State Marker is a 2 mile round-trip (1 hour) Blue-Blazed trail starts on flat Air Line Trail, to CT/MA stone border marker on right; then challenging uphill, rocky climb to historic tri-state marker erected in 1883. Off-shoot trails into RI & MA, connecting to Mid-State Trail & Douglas State Forest Loop Trail. No fee.
- Hiking/Walking/Strolling Trails
Thompson, CT 06277