In the early 1900s, paleontologists unearthed the Age of Mammals when they found full skeletons of extinct Miocene mammals in the hills of Nebraska — species previously only known through fragments. At the same time, an age of friendship began between rancher James Cook, the land owner where the fossils were found, and Chief Red Cloud of the Lakota.
Most of the land that is now Agate Fossil Beds National Monunent was once part of the Agate Springs Ranch, owned by James and Kate Cook. They bought the ranch from her parents in 1887, a few years after they found what they called “a beautifully petrified piece of the shaft of some creature’s leg bone.”
In 1892, Erwin H. Barbour of University of Nebraska was the first scientist to examine the strange “Devil’s Corkscrews of Agate.” These were later recognized as the fossilized burrows of Paleocastor.
In 1904, Olaf Peterson of the Carnegie Museum in Pittsburg was the first professional paleontologist to excavate in the ‘great bonebed’ in the Fossil Hills. The American Museum of Natural History, Yale University, and other institutions also worked here between 1904 and 1923. The competition between these groups to find the best specimens were — in a word — spirited.
Paleocastor had powerful clawed forelimbs for digging and long, curved teeth like modern beavers. Herds of Stenomylus, gazelle-camels about two feet tall, grazed grasslands beside the three-toed, pony sized rhinoceroses Menoceras. The most common mammal in the bonebed, Monoceras may have roamed these plains in large herds. Only a few oreodonts, about the size of a sheep, have been found here. They are most common in the carnivore dens nearby, where they were the prey of beardogs.
Fossil remains of the ancestors of the modern horse, Parahippus, also have been found in the waterhole but are rare. Horses became extinct in North America millions of years after the die-off event at Agate, not to return until brought back by the Spaniards. Moropus was quite fantastic. Related to both the horse and the rhinoceros, it was large, had back legs shorter than the front, with great clawlike hooves. It probably browsed leaves of bushes and small trees.
Another large animal, Dinohyus, was a giant entelodont related more closely to cows and pigs than to carnivores. Tracks of this huge scavenger have been found in the waterhole mud. It broke bones with its teeth (bite marks show on chalicothere limb bone). Discoveries in the 1980s included fossil remains of beardogs and other carnivores and their dens — one of the few paleontological sites of this type in the world.
In animal populations, far fewer carnivores exist than herbivores, making their fossil remains relatively rare. When paleontologists from Carnegie Museum unearthed a number of carnivore remains at Agate Fossil Beds in 1905, it was a major event.
The most significant skeletons found were those of the beardog Daphoenodon Bones found in their dens showed the wolf- and hyena-like beardogs were the largest carnivores alive 22-23 million years ago in North America. They preyed on juvenile rhinos, camels, and small sheep-like oreodonts. The beardogs of Agate lived here during and after the droughts represented in the bone bed.
The story might have ended there, but in 1981, University of Nebraska scientists, while searching for the site of the original discovery, found underground dens containing fossil of beardogs and other carnivores. These burrows are the oldest known record of denning behavior in large mammal carnivores.
The Visitor Center has superb displays of the recreations of the site’s former inhabitants, including beardogs, Moropus, Menoceras, Dinohyus and Paleocastor.
Don’t let the name fool you. Agate Fossil Beds National Monument features more than world-class fossil exhibits. Also in the Center is The James H. Cook Collection of Lakota Artifacts, a truly amazing set of artifacts and personal items donated by historically significant figures such as Red Cloud.
James H Cook first arrived in western Nebraska in the early 1870s. He worked as a cattle driver, or cowboy, for a Texas outfit. The 17-year-old’s chance meeting with a 53-year-old Red Cloud didn’t happen until 1874. It was arranged by Baptiste “Little Bat” Garnier, a mutual friend. As the story goes, fossils played a vital role in that meeting.
O.C. Marsh, a Yale University paleontologist, was hoping to collect fossils from north of the Red Cloud Agency, near present-day Fort Robinson State Park. According to James, who’d previously learned Indian sign as well as some of the Sioux’s spoken language, he met and spoke with Red Cloud and other Lakota leaders on behalf of Marsh. In addition to exposing him to fossils, this chance encounter between James and Red Cloud developed into a friendship that lasted until the Red Cloud’s death in 1909.
The friendship between the well-known Lakota leader and his people after 1887 led them to visit James Cook at Agate Springs Ranch in Niobrara County. It was a 150-mile journey by horse and wagon from the Pine Ridge Reservation. To come and go from reservation, they needed a pass from the reservation agent. They stayed at the ranch, erecting tipis on the flats east of the Cook’s home. The Lakota also helped around the ranch by hunting game, tanning hides under trees near their house while sharing stories of life’s adventures which they had shared together before.
It was during these visits, too, that the Lakota, Northern Cheyenne, and others gave gifts to James and his family, often in return for receiving beef and hides they later tanned and painted. Some of these gifts were made especially for the Cooks, including buckskin suits for James’ sons Harold and John, gloves, and the painted hide showing the Battle of Greasy Grass, also known as Custer’s Last Stand. Other items—Red Cloud’s shirt, three generations of the Red Clouds’ pipe bags (one each belonging to Red Cloud, his father, and his son), one of Crazy Horse’s whetstones and the war club owned by American Horse, said to be the very weapon which knocked down Captain Fetterman before he killed himself.
James and his descendants believed these gifts should remain in the vicinity of the family home. They were presented to the National Park Service after James’ son Harold passed away in the 1960s. When the current visitor center was built in the early 1990s, two rooms were dedicated to the James H. Cook Collection. One room introduces visitors to the ranch and the culture of the Oglala Lakota, while the second, a light- and climate-controlled room, displays many of the most important gifts. Historic photos exhibited along with these items illustrate the story of the friendship that developed between the Cooks, Red Cloud, and their families.
.