Thousands of years ago, North America’s earliest people hunted bison and made tools in an area 13 miles north of Guernsey now called Hell Gap.

Discovered accidentally by two students in the 1950s, Hell Gap is one of the most important paleoindian archeological sites in North America, said Marcel Kornfeld, a professor of anthropology at the University of Wyoming.

The stratified way cultural artifacts were preserved in the earth for thousands of years gives unprecedented information about paleoindian life across generations.

The importance of the site was recognized Jan. 11 when Interior Secretary Sally Jewell designated the site in Goshen County a national historic landmark, citing its contribution to knowledge about North America’s earliest people. It is the 27th national historic landmark in Wyoming and is one of 2,500 landmarks nationwide.

Judy Wolf, chief of planning for the Wyoming State Historic Preservation Office, said she instigated the nomination. She started her efforts in 2011.

“This is such an important site nationally,” she said. It is the only known paleoindian site in North America with artifacts from humans who lived 13,000 to 8,500 years before present.

Information gleaned from the site continues to teach archaeologists about the people who lived thousands of years ago in what is now Wyoming,.

Hell Gap is located in the Hartville Uplift near Guernsey and Manville. Two archaeology students accidentally discovered the site in the late 1950s, when they found themselves stranded after a rainstorm. They walked up a creek and found projectile points that would later become known as Hell Gap Points.

Excavation on the site began in the 1960s after the students showed the points to a professor at the University of Wyoming, Kornfeld said. The site attracted national attention and archaeologists from Harvard University also came to work at the site. Excavators found several hundred projectile points, hundreds of scrapers and tens of thousands of flakes — the remains from making stone tools.

Archaeologists also found rare beads from the paleoindian era. A total of 140 beads from this period have been found in the world. Three were at Hell Gap, one bone, one stone and one ochre.

Many items found during the 1960s were never fully reported. Other sites and projects drew the interest of researchers. Work at Hell Gap stalled. It wasn’t until the late 1980s that the site again piqued the interest of archaeologists, including Kornfeld.

Kornfeld started working at the site in the 1990s. He knew from the previous site work it was important, but there was still more to learn: What was life like? Did the people live in structures? Where did they get raw materials for tools? How did they process their food?

If there was any place that Kornfeld’s questions could be answered, it was at Hell Gap. Hell Gap offers more than a mile of artifacts from early cultures, preserved in a stratified manner, with evidence of one era on top of another. This type of preservation isn’t often found. Usually archaeological sites represent short periods, like a bison-kill area, where humans stayed briefly for an event like the butchering of an animal.

“What you had at Hell Gap is a place that people came back to again and again and again, for 4 or 5,000 years,” Kornfeld said. “It’s very different kind of information you are gaining about what past people were doing back then.”

The Hell Gap valley was occupied consistently through those thousands of years and archeologists have uncovered artifacts from nine different paleoindian cultures.

Archeologists found bone needles used for sewing clothes and post holes from structures that once stood in the area.

All of these items give clues about life 13,000 years ago to about 8,500 years ago, Kornfeld said.

The site is on property owned by the Wyoming Archaeological Foundation and is used for education. The national historic landmark designation could help in obtaining grants for work at the site, Kornfeld said.

But for Kornfeld, who helped write the landmark nomination, it’s mostly about the recognition of the importance of the site.

Each summer University of Wyoming students work at Hell Gap, trying to glean more information about the paleoindians. They know ancient people occupied the site throughout the year. But there is still more to learn about daily life thousands of years ago.

“Anyone can say ‘Look, there are some flakes there,’” Kornfeld said. “It takes a lot more to know what those flakes were actually doing there.”

This article has been updated with the correct spelling of ochre — Ed.