South Branch Ashuelot River

South Branch Ashuelot River
South Branch Ashuelot River
	The South Branch in East Swanzey
Location
Country	United States
State	New Hampshire
County	Cheshire
Towns	Troy, Marlborough, Swanzey
Physical characteristics
Source	Confluence of Rockwood Brook and Quarry Brook
• location	Troy
• coordinates	42°49′39″N 72°10′42″W / 42.82750°N 72.17833°W
• elevation	955 ft (291 m)
Mouth	Ashuelot River
• location	Swanzey
• coordinates	42°53′21″N 72°16′57″W / 42.88917°N 72.28250°W
• elevation	463 ft (141 m)
Length	17.4 mi (28.0 km)
Basin features
Tributaries
• left	Bridge Brook, Martin Brook
• right	Shaker Brook, Forbush Brook

The South Branch of the Ashuelot River is a 17.4-mile-long (28.0 km)^[1] river located in southwestern New Hampshire in the United States. It is a tributary of the Ashuelot River, itself a tributary of the Connecticut River, which flows to Long Island Sound.

The South Branch begins in the town of Troy, New Hampshire, at the confluence of Rockwood Brook and Quarry Brook. The river flows in a zigzag manner northwest, then southwest, then north to the Ashuelot River in Swanzey. On the river's northwest-flowing leg, it drops rapidly as it cuts a deep, narrow valley through the highlands of Troy and Marlborough. New Hampshire Route 12 and an abandoned railroad line follow the river along this section. When the river turns southwest, the valley widens, except for a brief section where the river passes the village of East Swanzey. The final, north-flowing leg of the river is through a broad, flat intervale, where the river makes numerous tight meanders.