Beaver Brook Reservation is a public recreation area covering 303 acres (123 ha) on the dividing line between the town of Belmont and the city of Waltham, Massachusetts.

The state park is managed by the Massachusetts Department of Conservation and Recreation.

A portion of the reservation was owned by the landscape architect Robert Morris Copeland (1830-1874),[4] whose 19th-century home sits within the park.

Other points of historical interest include a monument to the Waverly Oaks and the remains of a 19th-century fulling mill.

[5] In addition to a bike path, playing fields, woodlands, wetlands, a cascading waterfall, wading pool, and fishing opportunities, the reservation offers programs on wildlife and cultural history.