Near Broadus in Powder River County, Montana — The American West (Mountains)

The Hell Creek Formation

Photographed by Barry Swackhamer, July 18, 2021

1. The Hell Creek Formation Marker

Inscription. About 65 million years ago, the Western Interior Seaway receded as the Rocky Mountains rose, pushing the shoreline further east. Great rivers meandered through the coastal plain in a warm and humid climate, depositing sediment which would later become known as the Hell Creek Formation. The tan sandstones, siltstones, and mudstones are common throughout eastern Montana, but can be best seen in road cuts along the highway, the Charles M. Russell Wildlife Refuge, and in Makoshika State Park. Dinosaur fossils are frequently found in the Hell Creek Formation and include Triceratops, an immense hadrosaur called Edmontosaurus, the thick-skulled Pachycephaosaurus, the armored Ankylosaurus, and the awesome Tyrannosaurus rex to name just a few. The boundary between late Cretaceous Hell Creek Formation and the more recent Tertiary Fort Union Formation provides evidence that a gigantic meteorite or asteroid struck the Earth about 65 million years ago. But it is not known if that event caused the extinction of the dinosaurs or just hastened their journey to oblivion. Fossils excavated and studied in Montana from the Hell Creek Formation

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have added immeasurably to our knowledge about the dinosaurs and their lives.

Erected by Montand Department of Transportation.

Topics. This historical marker is listed in this topic list: Paleontology.

Location. 45° 25.301′ N, 105° 23.815′ W. Marker is near Broadus, Montana, in Powder River County. It is on U.S. 212 south of Big Powder River East, on the left when traveling north. The marker is located near the visitors information center. Touch for map. Marker is in this post office area: Broadus MT 59317, United States of America. Touch for directions.

Regionally, this marker is in Southeast Montana, in Custer Country and in the Powder River Basin.

It is also in the American Mountain West,

in the Lewis & Clark Corridor,

on the Great Plains,

and specifically on the Northern Plains.

Globally, it is in North America,

the Western Hemisphere,

the Western World,

and the Anglosphere.

Historically, it finds itself in what was once Rupert’s Land

and also the Louisiana Purchase.

Other nearby markers. At least 6 other markers are within 2 miles of this marker, measured

Photographed by Barry Swackhamer, July 18, 2021

2. The Hell Creek Formation Marker

as the crow flies: The Powder River Country (within shouting distance of this marker); Big Sky Country (within shouting distance of this marker); Southeastern Montana (about 500 feet away, measured in a direct line); Let 'er Buck (approx. 1.6 miles away); A Community Formed (approx. 1.6 miles away); a different marker also named Southeastern Montana (approx. 1.7 miles away).

Also see . . . Hell Creek Formation -- Wikipedia. The Hell Creek Formation is an intensively studied division of mostly Upper Cretaceous and some lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana. The formation stretches over portions of Montana, North Dakota, South Dakota, and Wyoming. In Montana, the Hell Creek Formation overlies the Fox Hills Formation. (Submitted on December 30, 2021, by Barry Swackhamer of Brentwood, California.)

Map of the Hell Creek Formation image. Click for full size.

Photographed by Screenshot

3. Map of the Hell Creek Formation

Credits. This page was last revised on December 27, 2024. It was originally submitted on December 30, 2021, by Barry Swackhamer of Brentwood, California. This page has been viewed 2,459 times since then and 214 times this year. Photos: 1, 2, 3. submitted on December 30, 2021, by Barry Swackhamer of Brentwood, California.