Cannonball Concretions Pullout

Overview

A few miles into the North Unit, right across from the Juniper Campground entrance, this signed pullout lets you step into a patch of badlands strewn with giant stone “cannonballs.” Most folks pop out for 10–20 minutes, snap photos, and move on—yet it’s one of the park’s most memorable quick stops.

Geology 101

These spheres formed as minerals cemented sediments around a core and grew outward—think pearl in a shell—before erosion peeled them out of the butte and onto the slope. Some are volleyball-sized; others approach small‑car scale, and many more are still embedded in nearby hillsides.

What to Expect

A short sidewalk leads to an interpretive exhibit and easy viewing. Beyond that, it’s open, unpaved terrain where the clay can be steep and slick—especially after rain or snowmelt—so wear grippy shoes and skip climbing when it’s wet. It’s illegal to remove or deface rocks or any other natural features. Service animals are permitted on a 6‑foot leash.

Wildlife

Bison frequently wander right through here—give them a very wide berth and wait out any bison jams. You might also spot prairie dogs nearby. Ticks are possible; do a quick check after exploring.

Trail Option

If you’re feeling it, this spot also serves as a start point for the 11.4‑mile Buckhorn Trail. Even a short out‑and‑back adds more concretions and big‑sky views. Bring water, sun protection, and be self‑sufficient—the North Unit is remote.

Facilities

There are no restrooms or water at the pullout. Plan your bathroom and refill stops at other North Unit facilities.

Best Time to Visit

Conditions are best when dry. Golden hour light (early or late) makes the spheres pop and keeps summer heat at bay. Weekends late morning can be the busiest; aim for early morning or late afternoon for fewer people. The area is accessible day and night if you’re chasing twilight or stars.