Big Timber in Sweet Grass County, Montana — The American West (Mountains)
Montana's Jurassic Park
The sauropods were preyed on by Allosaurus, a large meat-eating dinosaur that
Jurassic fossils are found in the Morrison Formation, sandstones and mudstones that were deposited about 155 to 150 million years ago. At that time, this part of Montana was a vast coastal plain that bordered the southern edge of the shallow inland sea. The Morrison Formation consists of layers of sandstone deposited by rivers alternating with lakes of mudstone, which originated as river flood plains. Most of the exposures of the formation in Montana are around the edges of mountain ranges, like the Crazy Mountains to the northwest.
• The inland sea was populated by marine reptiles like I•chthyosaurus and the long-necked Plesiosaurs.
• Diplodocus was not only the largest known dinosaur in North America during the Jurassic times, it is also one of the most common fossils found in the upper Morrison Formation.
• Although some paleontologists
• You can see fossils of Jurassic dinosaurs at the Museum of the Rockies in Bozeman and the Great Plains Dinosaur Museum in Malta.
Erected by Montana Department of Transportation.
Topics. This historical marker is listed in this topic list: Paleontology.
Location. 45° 44.145′ N, 109° 45.377′ W. Marker is in Big Timber, Montana, in Sweet Grass County. Marker is on Interstate 90 at milepost 377, on the right when traveling west. The marker is located at the westbound Greycliff Rest Area. Touch for map. Marker is in this post office area: Big Timber MT 59011, United States of America. Touch for directions.
Other nearby markers. At least 8 other markers are within 12 miles of this marker, measured as the crow flies. The Ca(title obscured) 1866 (here, next to this marker); The Crazy Mountains (original title obscured) (within shouting distance of this marker); The Crazy Mountains (within shouting distance of this marker); Captain Wm. Clark (within shouting distance of this marker); a different marker also named Montana's Jurassic Park (about 700 feet away, measured in a direct line); The Bozeman Trail (about 700 feet away); The Thomas Party (approx. 2 miles away); St. Mark's Episcopal Church (approx. 11.6 miles away). Touch for a list and map of all markers in Big Timber.
Credits. This page was last revised on January 25, 2022. It was originally submitted on January 25, 2022, by Barry Swackhamer of Brentwood, California. This page has been viewed 204 times since then and 82 times this year. Photos: 1, 2. submitted on January 25, 2022, by Barry Swackhamer of Brentwood, California.