Imagine a creature roughly approximating a beaver or large prairie dog but one that digs holes in a spiral nearly 10 feet deep, forming tunnels resembling a corkscrew or drill bit: this is the curious activity of the prehistoric paleocastor, which lived between 20-30 million years ago in the area now situated in present-day northwest Nebraska. A handful of these “Devil’s Corkscrews”—can be seen up-close on the Daemonelix Trail, one of two hikes in Agate Fossil Beds National Monument. (Note: The other is the 2.8-mile Fossil Hills Trail.) This historic trail also features some of the park’s nicest panoramic vistas, with views across the bluffs and badlands to the Niobrara River Valley and beyond.

The hike

The Daemonelix Trail begins from the first pull-off on the left after entering Agate Fossil Beds National Monument on River Road. The parking lot includes several waysides highlighting nearby attractions in Nebraska, South Dakota, and Wyoming, as well as a map of the one-mile stem-and-loop trail. The easy, pebbled track begins by setting out northward toward the sandstone and limestone bluffs, passing under telephone lines and coming adjacent with a clutch of wavy stones on the right that are remnants of an ancient sand dune.

Beyond, sunflowers line the trail—which is now composed of mostly red dirt—and the loop section begins at 3/10 mile. Follow the arrow pointing left to tackle the circuit in a clockwise direction. Edging a bluff on the right, the path comes to a wayside and the face of a cliff with the remnants of several Daemonelix, the curiously-crafted burrows of ancient paleocastors.

While the burrows from this wall have largely been removed, one can see a preserved corkscrew minutes later: here a clear case about the size of a telephone booth protects a fossilized Daemonelix some 4-5 feet tall. Many of these spirals were excavated by the Carnegie Museum in the late 19^th century, years before the discovery of many larger mammal remains at nearby Carnegie Hill and University Hill.

From here the Daemonelix Trail climbs and wraps around a left-hand bend, with bluffs on the left and a gulch on the right. Indian ricegrass and yuccas dot the largely arid landscape. After a right-hand turn and the sharpest climb of the hike, the route crests a local summit. From here a panorama unfolds, with views east to Carnegie and University Hills, south to the Niobrara River and Agate Springs Ranch, and north in the direction of Pine Ridge and South Dakota. The overlook from atop this limestone perch is among the best in the park.

When ready, continue down the chalky path, soon returning to rosy soil and switchbacking down to a low saddle below two outcrops. Here there is a bench and another encased set of corkscrews, this one a split Daemonelix, leading to two separate nesting chambers. Ancient plant roots and insect burrows can be also be spotted along the exposed sandstone cliffs.

From here the trail courses downhill again, passing the initial bluff on the right and returning to the start of the loop section. By now hikers have travelled about ¾ mile. Bear left here, retreading down the well-worn path, passing the sand dune outcrop on the left and returning to the parking area along River Road. All told, this easy trail with some mild ups and downs clocks in at about one mile, making for a 30-minute-to-an-hour adventure in Agate Fossil Beds.