Gate 40 is an access point to the Wachusett Reservoir located on the northern shore of the reservoir, near the town of Sterling. It offers a view of the water and the surrounding hills. Many visitors come to Gate 40 to enjoy fishing, hiking, and birdwatching. The gate is open year-round, from sunrise to sunset.

Wachusett Reservoir, along with the Quabbin Reservoir and Ware River, is an unfiltered source of high-quality water for the Massachusetts Water Resources Authority water supply system. The 65-billion-gallon reservoir covers 108 square miles with 37 miles of shoreline. Recreational activities are regulated and limited to protect 3 million people’s drinking water.