Caprock Coulee Nature Trail

Caprock Coulee Nature Trail is a 1.6-mile out-and-back through a steep, narrow coulee in the North Unit. The walk to its marked end is about 0.8 mile; return the same way. Plan roughly an hour to an hour and a half if you stop at the numbered interpretation stations. It is a good choice when you want a close look at the badlands without taking on the full Caprock Coulee loop.

Start at Caprock Coulee Trailhead on Scenic Drive. The path drops into a water-cut valley, then winds across open slopes and a shaded north-facing hillside. At the first fork, take the left branch; the right-hand path joins Buckhorn Trail. Turn around at post 21, marked Trail's End. Continuing beyond it takes you onto the longer Caprock Coulee loop, a different hike. Dogs are not allowed on trails in the park, including this one.

A coulee is a steep, narrow valley carved by water. The numbered stops show that work in miniature: runoff cuts rills and piping holes into the walls, while blue-gray bentonite—clay formed from volcanic ash—swells when wet and can slump. A dark lignite seam and pale petrified wood show what lies inside the layers; the wood is about 55 million years old, likely from cypress or magnolia trees that grew when this region was swampier. At the deeply ribbed clay wall, look across the gully so the erosion grooves stand out in a photo.

Prairie grasses and sagebrush cover the open ground; the cooler, shaded north-facing slope has junipers and green ash. The interpretation points out three kinds of sagebrush by their different leaves and scents, plus prickly pear, chokecherry and lichens. Chokecherries ripen dark purple in late summer. The short walk makes it easy to slow down and compare how much the plants change over a few hundred yards.