Our Mill River is a tributary of the Connecticut River, New England's longest at more than 400  miles in a watershed of 11,000 square miles that forms the spine of New England and runs from Quebec to Long Island Sound.

Connecticut River Watershed in Northeast Region

Mill River in the Connecticut River Watershed

There are hundreds of Mill Rivers in America and at least a score of them in the Connecticut River watershed. Our Mill River (in red letters), runs about twenty miles from headwaters in the hilltowns on the east slope of the Berkshire Hills into Williamsburg, thence into Northampton and Easthampton.Below is a map of the Mill River Watershed from its headwaters on the West Branch at Highland Lakes in Goshen and on the East Branch in the vicinity of Keyes Swamp in Conway down to its mouth at Hulburt's Pond, Easthampton where it empties into the Connecticut River Oxbow.

The watershed encompasses about 33,000 acres (52 sq. miles), centered on Goshen, Williamsburg, and Northampton, and including parts of Westhampton, Chesterfield, Ashfield, Conway, Whately, and Hatfield. No other landscape feature was more important in shaping the ecology, history, and settlement patterns of the area, especially in Williamsburg and Northampton.

The headwaters of the West Branch are in the Lower and Upper Highland Lakes (reservoirs) in the town of Goshen. The headwaters of the East Branch are in the town of  Conway. Devil's Den is a beautiful cascading former mill site near the Goshen-Williamsburg border. Searsville, on the West Branch in Williamsburg, is the uppermost former mill village and original town center. Williamsburg Center is the confluence of the East and West Branches and the current town center. Skinnerville is the former site of a silk mill village, and Haydenville became the most important industrial village in Williamsburg.

After Haydenville, the river crosses into the City of Northampton and runs through the mill village of Leeds, site of the only natural waterfall in the river (Cooks Dam) and famous in the 19th century for its textiles. About two miles downstream is Nonotuck Dam where the mill village of Florence was founded. Then come two more dams, the first at Bay State (tool manufacturing) and the second at Paradise Pond where the "Upper Mills" was established in 1666.

Less than a half mile from Paradise Pond, just below the West Street Bridge, the Corps of Engineers diverted the Mill River away from downtown Northampton directly into Hulbert's the the Connecticut River Oxbow. The watershed map shows that the river originally ran through the Lower Mills (the first mill dam in Northampton) and past Lickingwater (the original shallow ford across the river).

The green river bed below Lickingwater shows the river bed when the English first arrived, and the red line depicts the river's first diversion in 1710 directly into the Connecticut River.


Tumbling out of its headwaters at Upper Highland Lake in Goshen at 1,440  feet above sea level, the river’s West Branch drops 910 feet to Williamsburg at 530 feet, where it meets the West Branch flowing out of Ashfield, then down another 105 feet to Haydenville at an elevation of 425 feet.  Picking up tributaries from Beaver Brook and Roberts Meadow Brook, it drops 95 feet to Leeds at 330 feet, then another 100 foot drop to Florence at 230 feet, down to Paradise Pond at 130 feet, slowly dropping a final 20 feet to the meadows of the Connecticut River at 110 feet above sea level.  That is a total drop of 1,390 feet from Goshen to Northampton.

Current Information on Water Quality, Discharge and Precipitation:

Water Quality Data from the Connecticut River Watershed Council and the Pioneer Valley Planning Commission at the rope swing site inBay State .

Smith College's Monitoring Station at Paradise Pond: Water and air temperature, water turbidity, pond level, and stream discharge.
Paradise Pond data from the Geology Department at Smith College:
Live webcams of Smith College and Paradise Pond.
Discharge data from the US Geological Survey between Clement St. Bridge and Smith College.

Watershed Area: 52.6 square miles

Total from Upper Highland Lake to Oxbow: ca. 20 miles
Hulburt’s Pond (Arcadia) to South St. barrier: 1.47 miles
South St. barrier to Felt Building: .64
Felt Building to Paradise Pond: .39
Paradise Pond to Clement St. Bridge: 1.97
Clement St. Bridge to Nonotuck Dam: 1.26
Nonotuck Dam to Meadow St. Bridge: .35
Meadow St. Bridge to Look Park downstream: .90
Look Park downstream to Look Park upstream: .77
Look Park upstream to Cook’s Dam: .28
Cook’s Dam to Haydenville: 2.4
Haydenville to Williamsburg confluence: 1.9

Total Hulburt’s Pond to Williamsburg: 12.33

East Branch to source in Conway: 6.1
West Branch to Lower Highland Lake: 6.2

Upper Highland Reservoir/Goshen
Lower Highland Reservoir/Goshen
Searsville Reservoir/Searsville-Williamsburg (breached)
Brassworks/Haydenville (breached)
Leeds Upper Dam (breached)
Leeds Middle Dam
Cook’s Dam/Leeds
Nonotuck Dam/Florence
Bay State Village (breached)
Paradise Pond/Northampton
South Street Bridge barrier