The Winsor Dam and Park Headquarters are located at the southern end of the Quabbin Reservoir. The dam was built in the 1930s as part of the Quabbin Project, which involved the flooding of four towns and the relocation of thousands of residents. The park headquarters, also built in the 1930s, is a historic building that serves as a visitor center and museum for the reservoir. 

The Visitor Center is located in the Administration Building which was built in the 1930’s. The building was originally intended to be administrative offices and living quarters for Metropolitan District Commission (MDC, the predecessors to the DCR) employees, as well as MDC police (there is still a jail cell in the basement!). In the 1980s through the early 2000s, a series of divisions in the MDC established the Department of Conservation and Recreation, the Massachusetts Water Resource Authority, and the Massachusetts State Police, all of which are still here. Today the building houses not only the administration for the Quabbin Reservoir and Watershed, but also engineers, biologists, and many other people whose jobs are vital to the mission of the Quabbin. Exhibits, videos, and other resources are located in the Visitor Center. 

Winsor Dam was named for Frank E. Winsor, the chief engineer of the project. It was constructed from 1935 to 1939 and was a marvel of engineering at the time. It is 2,640 feet across and used 4 million cubic yards of hydraulic fill to build. A concrete caisson wall was constructed to support the dam and reaches down to the bedrock at a maximum depth of 120’. The dam is also designed to release a minimum of 20 million gallons per day (required by law) to maintain the Swift River through a bypass system. The amazing process by which this structure was built was documented and photographed and can be found at the Visitor Center.

The Quabbin Reservoir is a remarkable engineering feat that provides water to millions of people in Massachusetts. It was constructed in the 1930s by damming the Swift River and flooding four towns in the process. The reservoir covers an area of 39 square miles and has a capacity of 412 billion gallons. The Quabbin Reservoir is a popular destination for fishing, hiking, and wildlife viewing. The reservoir is surrounded by a protected forest that hosts a variety of plants and animals, some of which are rare or endangered. 

Quabbin Reservoir is one of the largest unfiltered water supplies in the United States. Along with the Wachusett Reservoir and Ware River, it is the source of high-quality water for the Massachusetts Water Resources Authority water supply system. Recreational activities are regulated and limited to protect 3 million people’s drinking water.