Photo from email, March /07 - Quentin 

With headwaters in Lowell, Vermont, the Missisquoi River flows north into Quebec where the Missisquoi Nord joins the main stem at Highwater, Quebec.  The River then returns to Vermont at East Richford and flows west to drain in the Missisquoi Bay, an arm of Lake Champlain.
 
 The Missisquoi River has an 88 mile course and over 50-miles of tributaries (Black Creek, Trout River, Tyler Branch, and Mud Creek).

 The land use practices over the past centuries in the watershed have led to a degradation of the water quality in the river.

Missisquoi Bay which is bordered by Vermont and Quebec, and through which the Missisquoi River drains into Lake Champlain alone now accounts for over one third of all the non-point source phosphorus in Lake Champlain, more than all the other Vermont watersheds put together!

Phosphorus runoff, which comes from many sources including eroding stream banks and a lack of buffers on worked fields used for dairy farms, promotes excessive algae growth and impairs water quality.  Algae blooms in the bay in recent years have been severe enough to close beaches, impact tourism, and in some cases kill pets.

Missisquoi Bay which apart from the Missisquoi River also drains the Pike and Rock rivers drains 1,200 square miles of northwestern Vermont and southern Quebec. Almost sixty percent of the drainage area is in Vermont.
Missisquoi Bay extends from the delta created by the Missisquoi River into Quebec. Water from the Missisquoi joins the flow south into the inland Sea know as Lake Champlain.

The northern tip of Lake Champlain crosses the Canadian/American border where it drains the whole lake northwards into the Richelieu River.  This river travels diagonally across southern Quebec and joins the St Lawrence River at Sorrell, Quebec. 

The mighty St Lawrence River continues its journey via the Gulf of the St Lawrence to finally flow into the Atlantic Ocean.

Much of my info has come from Missisquoi River Basin Association  2839 VT Route 105   East Berkshire, VT  05447  (802) 933-9009, or email MRBA@pshift.com

Tributaries

Black Creek, Trout River, Tyler Branch, and Mud Creek

Other Vermont River Information for fun.

Connecticut River 11,100 sq. miles
Major cities: Hartford, CT, Springfield, Chicopee and Deerfield, MA, and Brattleboro, VT
The Connecticut River is New England's largest river ecosystem and one of the Nation's first American Heritage Rivers. Its watershed encompasses over 11,000 square miles of wild, rural and urban lands in parts of four states flowing through New Hampshire, Vermont, Massachusetts and Connecticut. The Connecticut River carves a sinuous, shimmering pathway south from Fourth Connecticut Lake in New Hampshire at the Canadian border - past forested mountains and small hamlets, through rich farmlands and large cities - 410 miles later into Long Island Sound. The river forms the entire border between the States of Vermont and New Hampshire, and was immortalized in many of the most influential paintings of the "Hudson River school" painters around the turn of the 20th century. Also worth noting, the Quabbin Reservoir, which supplies drinking water to Metropolitan Boston, is part of the Connecticut River watershed

 St. Francois. 590 sq. miles
Major cities: Orleans, Vermont
The Black, Clyde and Barton Rivers drain a portion of northern Vermont through Lake Memphremagog, which is partly in Vermont and mostly in Quebec which then drains into the St Francis River which flows into the mighty St Lawrence River in Quebec, Canada which eventually flows into the Atlantic Ocean.

 White River.  The White River used to be a main Native American route between lower New England and Montreal, but as a walking trail, not a canoe route.

 The Missisquoi River is a tributary of Lake Champlain, approximately 80 mi (130 km) long, in northern Vermont in the United States and southern Quebec in Canada. It drains a rural area of the northern Green Mountains along the US-Canada border northwest of Lake Champlain, passing through no major population centers. The river is mostly within Vermont, skirting into Quebec for approximately 15 miles (24 km) in its upper couse. It rises in western Orleans County, Vermont southwest of Lowell near Belvidere Mountain, then flows north past Troy and North Troy before briefly entering Quebec, where it loops to the southwest to reenter Vermont in northeastern Franklin County. It flows west through northern Franklin County approximately 10 miles (16 km) south of the Canadian border, past the small communities of East Berkshire, Enosburg Falls, and Sheldon Springs. On the west side of Interstate 89 in northwestern Franklin County, it turns to the north, passing through Missisquoi National Wildlife Refuge in its lower 5 miles (8 km) before entering the south end of Missisquoi Bay, an arm of Lake Champlain that straddles the international border.

From Wikipedia, the free encyclopedia.