Cannonball Concretions

The Achenbach Trail Loop plunges you deep into the wild heart of Theodore Roosevelt National Park's North Unit, offering a true badlands adventure. This challenging route winds through dramatic geological formations, past cottonwood trees along the river, and across open prairie, with highlights like the Cannonball Concretions and sweeping views of the Little Missouri River from upper sections of the trail. You'll encounter unmaintained sections and two river crossings, making it a rugged and immersive experience.

This difficult 18.7-mile (30.1 km) hike, with 1904 feet (580 metres) of elevation gain, typically takes around 8 hours and 25 minutes. It's designed for experienced hikers ready for a full day or even an overnight trip. Access points include Juniper Campground or the Cannonball Concretions parking lot; be sure to check with park rangers about river conditions and carry plenty of water, especially in warmer months.

What makes the Achenbach Trail Loop notable is its raw, untamed character, providing a sense of solitude rarely found on more popular trails. You'll be sharing the landscape with abundant wildlife, including bison, pronghorn, and elk, adding to the backcountry feel. This is a prime choice if you're seeking a demanding, multi-faceted hike that showcases the unique beauty of North Dakota's badlands.

Explore the diverse Buckhorn Trail Loop in Theodore Roosevelt National Park, a moderate 11.1-mile hike through badlands and prairies.