The Passumpsic River () is a tributary of the Connecticut River, in Vermont. Though primarily a Caledonia County river, it is the only river to flow through all three counties of the Northeast Kingdom.
Course
The river arises in two branches: east and west. The East Branch begins just north of East Haven. It flows southwest through Hartwellville in East Haven, then into East Burke.
The West Branch starts as several small forks near Crystal Lake, northeast of Sutton. The Montreal, Maine and Atlantic Railway lines follows the West Branch of the Passumpsic until it converges with the East Branch in Lyndonville.
From Lyndonville, the river proceeds southerly through St. Johnsbury Center, St. Johnsbury, Passumpsic, and Barnet, and into the Connecticut River near Nine Island.
East Branch
The East Branch originates about 1/2 mile southeast of Sukes Pond, Brighton, in Essex County. Route 114 nearly parallels it as it runs south-southeast. It soon enters Caledonia County. It is joined by Jack Brook near Howard Brook Road in Newark. It then turns south southwest.
Just before entering East Haven, it is joined by Mill Brook/King Brook entering from the east. It is then joined by the confluence of Bean Brook and Whetstone Brook just inside the town of East Haven, back in Essex County. It goes through Hartwellville, in the town of East Haven, then crosses into Caledonia County for good.
In Burke, a mile downstream, it is joined on the south by Flower Brook which flows mainly from the east. Duck Pond drains into it. It is followed by Route 5A and flows through East Burke. It converges with the west branch before 5A joins US Route 5.
West Branch
The West Branch first exits out the west side of Newark Pond in Newark. It flows briefly through Barton, back into Newark, then into Burke.
Burke Mountain
The northeast and northwest sides of Burke Mountain drain into Dish Mill Brook, thence into the East Branch of the Passumpsic River. The southwest end of Burke Mountain drains into Mountain Brook, thence into the East Branch of the Passumpsic River. The south slopes and southeast side of Burke Mountain drain into Weir Mill Brook, thence into Bog Brook, the Moose River, and the Passumpsic River.
Burke
It proceeds south-southwest. Arcadia Brook flows into it from the north near Arcadia Lane. West Brook flows into it from the northwest near VT 5A, which nearly parallels it from then on south. The river flows south from that point. After it crosses 5A going south southwest, another unnamed brook enters it from the east
Sutton River enters it from the southwest, near U.S. Route 5 at West Burke. Route 5 now nearly parallels it southbound. The river then turns south-southeast. An unnamed brook, which Brook Road parallels for a while, enters from the east.
Lyndon (west branch only) In Lyndon it passes through Folsom Village. Quimby and Calendar brooks enter from the west. The river turns south, near the Calendar Brook Road intersection with Route 5. The two branches merge near East Burke Road, just northeast of where VT 114 intersects with US 5.
Lyndon (after two branches merge)
The joined river continues south. The river turns west, even west-northwest at times. An unnamed brook enters from the north. The river turns south. Miller Run enters from the west. Miller Run Valley is a sufficiently prominent feature to be followed by Interstate 91 instead of Route 5. South Wheelock Branch enters from the west southwest just south of Riverside Court. The river proceeds to the Route 5 bridge and from there to the Vail Hydro Dam. The river runs southeast, then takes a turn west northwest, as the Sheldon River enters from the east.
The river encounters the Vail Hydro Dam and runs to a gravel pit. The Little Falls, about a mile above the Great Falls, have about a descent. The river proceeds from the gravel pit and railroad tracks to the Great Falls Dam downstream. It briefly widens to pond size south of Murray Circle.
It encounters the Great Falls Dam and runs downstream to the St. Johnsbury Pierce Mills Dam. Roberts Brook enters from the east. Stark Brook enters from the north and west, north of St. Johnsbury Center. A second Roberts Brook enters from the east. A third Roberts Brook enters from the west.
St. Johnsbury
The river proceeds through the center of St. Johnsbury from north to south. From its valley the higher lands rise on either side to the east and west. In the southern part of the town it is joined by the Moose River at St. Johnsbury, a large stream from the east, and the Sleepers River, a smaller tributary, from the northwest.