Tunxis State Forest is a Connecticut state forest located in the towns of Hartland, Barkhamsted, and Granby. The forest surrounds Barkhamsted Reservoir and borders the Granville State Forest in Massachusetts. The forest is used for hiking, mountain biking, cross-country skiing, fishing, hunting, and letterboxing. Several trails cross the forest, including the northern end of the blue-blazed Tunxis Trail.