AUGUSTA — Maine loon license plates are a free pass to state parks this weekend.

The purchase of the plates supports conservation and wildlife preservation efforts in Maine. Free admission to all 48 of Maine’s state parks and historic sites is the state’s way of saying thanks to Maine drivers who have bought loon plates.

Since the program’s inception by the Legislature in 1993, more than $17 million in loon plate proceeds has gone to the Maine Department of Conservation and the Maine Department of Inland Fisheries and Wildlife.