Hidden just off a long, dusty county road in northwest Nueces County lies a scientific resource that continues to amaze researchers more than 50 years after it was first discovered.

The site is a gravel pit that is home to a local mining company, and the resource is what seems to be a never-ending supply of a wide variety of fossils that date back more than 10,000 years.

For the past 30 years, the primary researcher at the site has been Dr. Jon Baskin, a professor in the Biology Department of Texas A&M University-Kingsville. Twenty years ago he was joined by Ronny Thomas, a laboratory coordinator at the university who has a master's degree in geology.

Fossils at the site are made available for educational purposes only through the generosity of the mining company's owners, Thomas said.

"(They) are wonderful people," Thomas said. "Essentially, the deal is I don't interfere with their operations and they donate the fossils for educational purposes. And there are a ton of educational purposes."

The owners requested that the name of the company be withheld from this article to protect the security of the site. The business is a closed site, and educational tours are only available by appointment in coordination with Thomas or Baskin.

But the company does more than just allow Baskin and Thomas access to the site and the fossils. Employees for the mining company are actually tasked with identifying fossils at different stages of the mining process, with some located and preserved still in the ground and others identified in a sifting process that prepares the gravel for transport.

Ruben Gonzales has worked with the company for 27 years, and he said before Thomas and Baskin arrived fossils were noticed but thrown away. Now, workers learn to quickly identify the difference between rock and fossil, and make an effort to protect what they can.

"It's good when we manage to pull out a good piece that's actually intact." Gonzales said. "We've dug up tusks, bones, teeth."

Although he is grateful for the support of the company, Thomas said the nature of the business sometimes leads to unfortunate results. In perhaps the most impressive find in the past 20 years, workers inadvertently damaged a mammoth tusk before it could be identified. Work stopped, however, and Baskin and Thomas were called to remove a second tusk and a complete mammoth skull.

"I call it 'salvage paleontology,'" Thomas said.

And while some damage may occur, Thomas noted that the existence of the fossils would not even be known without the cooperation of those workers.

Standing in a large room at Texas A&M University-Kingsville that was filled wall-to-wall and floor-to-ceiling with fossils of all shapes and sizes, Thomas admitted storage space is in short supply in the department. What creates the shortage, Thomas said, is that the mining site seems to be a bottomless pit in terms of fossil production. Thomas has gone to the site nearly every Friday since 1994, and he said he rarely returns without a bin full of new fossils set aside by the workers.

Those fossils are brought to the university, where they are cleaned, identified and measured. Scientists from all over the country partner with the department to conduct research on the fossils, and Baskin and Thomas conduct their own research at the university.

Most of the fossils identified are from the Pleistocene period, which came to a close 10,000 years ago. The Pleistocene was a time of continental glaciers, and South Texas was a much different place then, Thomas said. In contrast to the dry, hot conditions familiar to most South Texans, Nueces County featured lush, extensive grasslands.

"You could compare the climate to something similar to the Serengeti in Africa," Thomas said. "You've got everything - elephants, lions running around… you had to have enough to support all of these things."

Baskin explained the location is so perfect for finding fossils for the same reason it is so perfect for finding gravel.

"Where the gravel hangs up on the bars (in the river), the bones hang up on the bars, too," Baskin said.

Over the years, Thomas estimates they have removed fossils of 45-50 different species from the site.

Most were grazers drawn by the grassland, Baskin said. Those grazers ranged in size from the elephant-like mammoth to bison and horses. Researchers have also identified tortoises, armadillo and even an extinct form of a javelina. Predators were also drawn to the area, and Thomas said they have identified bones from bears, saber-toothed tigers and wolves.

"It's amazing how much stuff is out there," Thomas said.

When asked if there was one particular fossil that had impressed or surprised them, Thomas and Baskin were quick with the same answer.

"It's not so much any one, it's just that we find so many different ones. The diversity," Thomas said.

Baskin agreed.

"There's nothing surprising about what we're getting here," Baskin said. "It's just we're getting such an abundance of specimens that it's enabling us to look at things in a more scientific way to find out what they are."

And that abundance has led to another of Baskin and Thomas' passions - outreach education.

With more fossils than they could ever hope to need, Baskin and Thomas have partnered with other organizations to bring the fossils out of the laboratory and into local schools.

One of the most prominent displays was completed at the Northwest Branch Library in 2009. A large mural depicting Nueces County 13,000 years ago, along with a display box featuring a toe, foot, leg and shoulder blade of a mammoth are on permanent loan to the library from the university.

"The goal is for all the schools in this area to have maps, bones, boulders, rocks and minerals in the schools so they can be used," Thomas said. "We've got a really good program and try to reach a lot of kids and get them interested in science."

Thomas also sometimes takes students out to the mining site on Fridays and lets them sift through the gravel to look for fossils on their own. And for a site that keeps on giving, Thomas said that hands-on education for future generations may be the most important gift.

"When you take them out there and they actually find their own, whether it be a shell imprint or a piece of bone or a tooth or whatever, it means more," Thomas said. "It's real."