The Blackfeet Tribal Business Council has set a date for tribal members to vote on a Water Rights Settlement and Water Compact signed by President Obama late last year.
The measure would establish tribal water rights in all six drainages on the Blackfeet Indian Reservation, giving the tribe the ability to use, lease, contract or exchange water.
It also includes upgrades for the Four Horns Dam and Blackfeet Irrigation Project.
The total price tag for the dam upgrades is $420 million.
Leaders from the Blackfeet Tribe set a vote date of April 20.
The Water Compact has been in the works for almost 30 years.