The proposal calls for the town to cede over 700 acres of land to the U.S. Fish and Wildlife service.
Chatham is trying to secure a 6-month extension to respond to the 1,000 page plan.
Selectmen Sean Summers said the town has widespread support at the local and state level for the granting of an extension.
The decision on whether to grant an extension will be made within a week or so, according to Summers.