Montana

Montana is the source of most commercially sold Tyrannosaurus, Triceratops and hadrosaur material, all of it from private ranch land in the Hell Creek, Judith River and Two Medicine formations. The landowner owns the fossil; commercial digs run on a lease or a royalty agreement, and a courthouse-filed agreement is normal for anything large. Keep the agreement with the specimen — a Montana dinosaur without one is unsaleable to a serious buyer.

Montana's Antiquities Act (MCA Title 22, Chapter 3, Part 4) covers paleontological remains on land owned by the state: nobody may excavate or remove them without an antiquities permit from the Montana Historical Society, and permits go to museums, universities and qualified persons, with no amateur exception. State trust land (DNRC) therefore requires that permit, although the statute says permits for fossils that are not scientifically significant should not be unreasonably denied.

The Fort Peck area, the Charles M. Russell National Wildlife Refuge and the Missouri Breaks National Monument are federal and either closed (refuge) or restricted (monument); much of the Hell Creek badlands is a mosaic of private, state and BLM land, and the BLM rules apply on the BLM sections. Montana State Parks prohibit collecting.

Verify locally: whether a hobby-level DNRC recreational use licence covers surface collection of common invertebrates on trust land — DNRC's recreational-use page lists what the licence allows and fossils are not obviously among them.