The farm's 126 acres was considered particularly vulnerable to development.
Connecticut has added the largest dairy farm in the state to its farmland preservation program.
Oakridge Dairy in Ellington has conveyed the development rights to nearly 126 acres, banning use of the land for anything other than agriculture. The land is used to grow corn and hay to support the dairy's herd of about 4,000 cows.
Seth Bahler, general manager of Oakridge Dairy, said the family will stay in farming and wants to preserve as much farmland as possible.
The state is paying the Bahler family $1.1 million, with at least half reimbursed by the U.S. Department of Agriculture. The Town of Ellington will pay $370,000 for the land.
The farm's 126 acres was considered particularly vulnerable to development because it is flat and clear and is in an area of significant home construction.