It can be infuriating to lose your 18th century Connecticut River Valley ancestors. Logically, you would assume that they didn't move far from their original home. They should - in theory - be found within a town or two of where their descendants settled. Except it doesn't always happen that way. Connecticut River settlers tended to move up and down the river, driven by the call of open land. I've seen many shoreline residents disappear from the shore to end up in a northern corner of the state. So, how do you find them?
For some strange reason, settlers tended not to cross the river. It may simply have been too much of a challenge. As a result, you can often trace settlers by moving from town to town up the river. Check each town as you travel north. It's methodical and sometimes boring, but it should get you what you need.