Agate Fossil Beds National Monument

Under the grass-covered hills along the Niobrara River in western Nebraska, sedimentary beds contain a rich concentration of 19-million-year-old fossils. Captain James Cook discovered the fossil beds in 1878 and acquired the site, called Agate Springs Ranch. Since then, fossil bones from the site have been exhibited around the world, and in 1965 the ranch became Agate Fossil Beds National Monument.

Agate Fossil Beds National Monument
©National Park Service
The Agate Fossil Beds house an amazing concentration of ancient fossils.

At the beginning of this century, the ranch was a headquarters for two noted paleontologists. In 1904, O. A. Peterson from the Carnegie Museum began the first scientific excavations on a hill overlooking the site. The next year, Professor E. H. Barbour from the University of Nebraska excavated an adjacent hill. Their respective domains became known as Carnegie and University hills. The paleontologists found dozens of skeletons in their excavations, including a small type of rhinoceros that was new to science.

The site is probably an ancient waterhole where thousands of these drought-stricken animals, and various other species, died. Perhaps the strangest-looking creature was the Moropus, a heavily built mammal with the head of a horse, neck of a giraffe, torso of a tapir, front legs of a rhinoceros, and hind legs of a bear. The ferocious Dinohyus, or "Terrible Pig," was a monstrous beast more than seven feet tall and ten feet long.

A paved interpretive trail leads to quarry sites on Carnegie and University hills where the fossil layer is partially exposed, allowing visitors to see the fossil bones of ancient mammals in their natural state. Another trail leads to two sites that contain "devil's corkscrews," fossils that initially confounded paleontologists. The corkscrews turned out to be fossilized burrows built by palaeocastors, ancient beavers who were more like prairie dogs than modern-day beavers.

Except for livestock grazing the hills, the surrounding landscape is relatively wild, inhabited by mule deer, pronghorns, coyotes, and other animals. Cottonwoods and willows follow the river through the flat, open valley, which is carpeted with grasses and wildflowers.

Agate Fossil Beds National Monument Information

Address: 301 River Rd., Harrison, NE
Telephone: 308/668-2211
Hours of Operation: Open daily 8 a.m. - 6 p.m. Memorial Day through Labor Day; 8 a.m. - 4 p.m. throughout the rest of the year; closed Thanksgiving, Christmas and New Year's Day

Admission: $3; children under 16 free

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To learn more about national monuments, memorials, and historic sites, and other travel destinations in North America, visit:


Eric Peterson is a Denver-based author who has contributed to numerous guidebooks about the Western United States.