The exhibits and displays at the Great Plains Dinosaur Museum focus on the prehistory of Montana and western North America. Emphasizing Montana, and in particular paleontology from northern Montana, we welcome all visitors to “walk through” the ancient story of this region.
Highlights of our gallery include the Camarasaurus “Ralph”, and the stegosaur 
“Giffen”. Both of these fossil specimens are from the Morrison Formation. At approximately 150 million years old, these are some of the geologically oldest dinosaur fossils ever recovered from Montana. Of further scientific importance, “Ralph” is the first Camarasaurus ever found in Montana, and “Giffen” is the northernmost dinosaur fossil ever recovered from the Morrison Formation in North America.
Moving through geologic time, the Museum’s gallery jumps ahead to a time when much of middle North America was covered by an inland sea (and inland seas have occurred many times in North America’s ancient past). Swimming in this ancient sea were many familiar sea creatures such as numerous fish and sharks, but the coiled-shelled ammonites (relatives of squid and octopi, but with shells), marine crocodiles, and giant marine reptiles like plesiosaurs and mosasaurs ruled this watery realm.
Further ahead in time we come to an ancient coastal deltaic environment 
(much like the present day Gulf Coast region). This was the Judith River Formation, and it was home to Phillips County’s famed hadrosaur Brachylophosaurus. Brachylophosaurus lived in vast herds here in ancient Phillips County, and the best specimens of this dinosaur come from here. From “babies” to adults, we have them all. The most complete Brachylophosaurus, “Elvis” (on display at the neighboring Phillips Co. Museum and the Museum of the Rockies) was found about 30 minutes north of Malta. And the most famous dinosaur in the Museum is the Brachylophosaurus “Leonardo”. “Leonardo” is in the Guinness Book of World Records for being the most complete “mummy” dinosaur found to-date.
The Museum’s gallery ends with the Hell Creek Formation. Being the last formation from the “Age of Dinosaurs” in western North America, the Hell Creek Formation was home to the famed dinosaurs Triceratops and Tyrannosaurus. Though not as abundant in Phillips County, we have bits and pieces of the Hell Creek Formation here.
So geologically, our gallery has come nearly full in circle telling much of the story of the “Age of Dinosaurs” from Montana.