The North Dike is one of the structures that form the Wachusett Reservoir. It was built in the early 1900s to prevent the overflow of the Nashua River into the reservoir. The dike is about 3.7 miles long and has a height of 40 feet. It offers scenic views of the reservoir and the Wachusett Dam, which is the largest hand-dug dam in the world. The North Dike is a popular hiking destination, with trails along the forest roads and footpaths. 

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.