Watford City in McKenzie County, North Dakota — The American Midwest (Upper Plains)
Cannonball Mystery
Photographed by Susan Van Den Bosch, August 12, 2025
1. Cannonball Mystery Marker
The large, round rocks littering the ground and protruding from the butte are bizarre. They don't seem to fit with the rest of the landscape. Where did they come from?
These "cannonballs" were not carried here by flowing water or glaciers. Instead, they formed within the sediment layers of the badlands. Now, erosion is slowly exposing these buried treasures.
Notice how some cannonballs have completely eroded out of the butte while others are just being exposed. Even more lie deep within the rock layers, yet to be revealed.
There are small pockets of cannonball concretions throughout the park and the Little Missouri Badlands. These seen here are some of the largest and most impressive yet discovered.
How Do They Form?
Mineral-rich water deposits minerals as it seeps through porous sediment layers. The minerals act like blue, binding the sediments together and forming concretions.
Concretions form in many different shapes and sizes. Those that are spherical are called "cannonballs". For now, scientists can only guess why some concretions take on such spherical shapes.
Save the Cannonballs
These cannonball concretions have been a popular attraction for decades. Help make sure they are here for future generations to enjoy by leaving them as you
this page online
Topics. This historical marker is listed in these topic lists: Natural Features • Parks & Recreational Areas.
Location. 47° 35.784′ N, 103° 19.948′ W. Marker is in Watford City, North Dakota, in McKenzie County. It is on Scenic Drive, on the right when traveling west. This marker is located on Scenic Drive at the Cannonball Concretions pullout of Theodore Roosevelt National Park. Touch for map. Marker is in this post office area: Watford City ND 58854, United States of America. Touch for directions.
Regionally, this marker is in North Dakota’s Bakken Oil Patch. It is also in the American Lewis & Clark Corridor, on the prairies, and 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 Ruperts Land and also the Louisiana Purchase.
Other nearby markers. At least 8 other markers are within 4 miles of this marker, measured as the crow flies: North Dakota Badlands (approx. one mile away); The Long X Trail: A Dusty Trail to Greener Pastures (approx. 1.3 miles away); Tilted (approx. 1.4 miles away); Layers in Time / Portraits in Stone (approx. 2 miles away); The View that Launched a Park (approx. 2.3 miles away); Bentonitic Clay (approx. 2.9 miles away); Theodore Roosevelt National Park (approx. 3.4 miles away); Work in Progress / Better Together (approx. 3.4 miles away). Touch for a list and map of all markers in Watford City.
Other markers no longer nearby. Cannon Ball Concretions (was a few steps from this marker but has been permanently removed); Long X Cattle Trail (was approx. 0.8 miles
Photographed by Susan Van Den Bosch, August 12, 2025
2. Cannonball
More about this marker. The previous marker was not present
Related marker. Click here for another marker that is related to this marker.
Photographed by Susan Van Den Bosch, August 12, 2025
3. Cannonball
Photographed by Susan Van Den Bosch, August 12, 2025
4. Cannonball Mystery
Credits. This page was last revised on September 6, 2025. It was originally submitted on August 19, 2025, by Susan Van Den Bosch of Almond, Wisconsin. This page has been viewed 107 times since then and 34 times this year. Photos: 1, 2, 3, 4. submitted on August 19, 2025, by Susan Van Den Bosch of Almond, Wisconsin. • Bill Pfingsten was the editor who published this page.
