Along the Swift River, which forms the eastern border of the town, lies the Herman Covey – Swift River Wildlife Management Area. Several other brooks and ponds dot the town's landscape, with some marshy lands lying along the Broad Brook. Belchertown lies partially along the Franklin County line to the northeast, and along the Hampden County line to the south. It is bordered by Pelham to the north, New Salem to the northeast, Ware to the east, Palmer to the southeast, Ludlow to the southwest, and Granby and Amherst to the west. The town does not share a land border with New Salem, but borders the town's territory on the Quabbin Reservoir. The town's center lies east-southeast of the county seat of Northampton, northeast of Springfield, west of Worcester and west of Boston. Most of the population is centered around the town center, with most of the town being rural-residential, especially around the smaller ponds near the villages of Dwight and North Station. The nearest interstate to the town, Interstate 90, runs just south of the town, with exits in Ludlow and Palmer. The exit in Ludlow can be reached along Route 21, which terminates at U.S. Route 202 west of the town common. (Prior to the building of the Quabbin Reservoir, Route 21 extended north along North Enfield Road towards the town of Athol.) The Palmer exit can be accessed along Route 181, which links U.S. Route 20 in Palmer and Route 202 in Belchertown, where the latter turns northwards towards Pelham along the edge of the reservoir. The town is also crossed by Route 9, the major east–west route through central Massachusetts, which heads from Ware towards Amherst, passing just north of the town center. Interstate 91 runs can be reached on Route 9 about nine miles from the Belchertown/Pelham line. The New England Central Railroad and an abandoned line which once linked to the Massachusetts Central Railroad in Palmer pass through the town. The NECR carries freight on the line, though north of Belchertown it was a part of the Amtrak Vermonter service between Vermont and the rest of the northeast until being rerouted through Holyoke and Greenfield in 2014. There is a private airstrip, Metropolitan Airport, in Palmer, but the nearest national air service can be reached at Bradley International Airport in Connecticut. As of the census of 2000, there were 12,968 people, 4,886 households, and 3,517 families residing in the town.