Weir Hill in North Andover, Massachusetts, is a low mountain rising above Lake Cochichewick that preserves both a long human history and diverse natural habitats. Used by Algonquian peoples before European settlement, the area included a campsite identified archaeologically in 1968, and its name recalls fishing weirs in Cochichewick Brook. Settlers later cleared its slopes for grazing, while milldams on the brook supported lumber and gristmills in the 18th and 19th centuries. Today the 194-acre reservation, established as a park in 1968 and later enlarged, is valued for recreation, conservation, and habitats that support threatened plant species.