ahepp is correct, there is Baxter State Park which -- is actually not quite a state park and is instead administered as a quasi-independent concern that adheres to the goals of the original land grant to the state, which is to provide an accessible wilderness area to the people of Maine -- and there is katahdin woods and waters national monument which falls under the purview of the national park service. The katahdin woods and waters national monument is the result of the founder of Burts Bees buying up swaths of privately owned land over the years via a corporation and then ultimately donating that land to the national park service. While this seems like a good thing in general it's complicated by Mainers somewhat unique relationship to recreation on private land and the concept up here of "traditional use" versus a kind of chain reaction of regulated formal use practices that were triggered by the national monument designation.

The two parks border each other in areas and share some waterways.