PITTSBURGH - A Wyoming rancher donated 4,700 acres of land rich in dinosaur fossils to the University of Pittsburgh, which will maintain it for students and researchers.

Allen Cook of Wheatland said he decided to donate the land, worth about $7 million, after he had it appraised in preparation for selling part of his ranch. The appraiser put Cook in touch with Alec Stewart, dean of the university's honors college and the appraiser's graduate school classmate.

"The amazing thing is that Cook, who had absolutely no connection with the University of Pittsburgh, had decided that we would be good stewards for this treasure," Stewart said Tuesday.

Cook said the university's interest "seemed kind of in line with what I'd like - that the land would be preserved."

The land is "littered with fossils," said Mary Dawson, a paleontologist at the Carnegie Museum of Natural History who visited the ranch several years ago.

"They have a real gem out there," she said.

Cook said he didn't realize that many of the rocks were fossils.

"The bones, they look like rocks because they have lichens on it," he said. Once he learned what to look for, "then it's easy to see."

Wyoming is incredible for paleontology because it's moderately arid, well exposed and the ground is not heavily covered by vegetation, Dawson said. Its rocks also represent a broad range geologic time, she said.

Cook, 57, bought the ranch about 40 miles north of Laramie in the 1980s and said it had long been grazing land. He said he pondered the deal with the university for a couple of years and finalized it in mid-December. He still owns about 92,000 acres.

The university "went the extra mile to show what they were going to do would be to the benefit of a lot of people," Cook said.

Stewart called Cook "a quintessential Westerner, a straight-talker whose handshake means a lot to him. But he also loves his land."

Details of how the university will use the land and of the partnerships it will form with the University of Wyoming remain to be worked out, Stewart said, but it's possible that students could begin going out to conduct survey work this summer.

The honors college already has a program on the other side of Wyoming, where students explore the geological, ecological and cultural dimensions of Yellowstone National Park and the surrounding area. The ranch will expand that, Stewart said.

The Carnegie Museum, which will partner with Pitt, has a long history with dinosaur fossils. It has one of the top collections in the world, and its dinosaur hall was built in 1907 by steel magnate Andrew Carnegie. Carnegie caught dinosaur fever after reading of the discovery of dinosaur bones in Wyoming.

Stewart has been out to scout the property, which is five times as large as New York City's Central Park. He called it an "American treasure," noting that it's largely undisturbed and contains dinosaur fossils, American Indian archaeology and geological features.

"It's got all the 'ologies,"' Cook said.