If you carefully keep your bird records by state, be aware of the location of the state line and use the appropriate eBird hotspots when you submit checklists. 

“When the bulk of the Connecticut River freezes over, the desperate duck can often find open water at the big bend at Vernon Dam. The stretch of river for more than a mile downstream from the dam can be busy with waterfowl from October through April.”
Birdwatching in Vermont, pp. 92-93.

Canada Goose, American Black Duck, Mallard, Common Goldeneye, Barrow’s Goldeneye, Common Merganser, Bufflehead, Ring-necked Duck, Hooded Merganser, Bald Eagle.

The Vernon Dam is a hydroelectric power plant located on the Connecticut River in Vernon, Vermont and Hinsdale, New Hampshire. It was built in 1909 and has a generation capacity of 37 megawatts with 10 turbine units. The dam creates a 2,550-acre reservoir that extends 26 miles upstream and has 8 feet of useable storage. The dam also has a fish ladder and a viewing window for visitors.