'Big Pig Dig': In 1994, two hikers discovered a 34-million-year old site in South Dakota's Badlands with fossils of prehistoric rhinos, small horses and huge carnivorous pigs

Two hikers taking an afternoon walk in South Dakota in 1994 had no idea they were about to uncover a prehistoric mystery buried beneath the Badlands. Steve Gasman and Jim Carney spotted massive bones near the Conata Picnic Area in Badlands National Park — and instead of disturbing them, they marked the location and alerted park authorities.

That simple decision triggered years of scientific research and excavations, eventually leading to the recovery of more than 19,000 fossils from a site now known for the “Big Pig Dig.”

A chance discovery during a hike

Gasman and Carney were walking along a dirt path when they noticed what appeared to be enormous bones exposed by erosion. Rather than trying to dig them out, the hikers recorded the coordinates and reported their discovery to park officials.


When paleontologists investigated, they realized the bones were part of something much larger. The surrounding area contained an extraordinary concentration of fossils preserved in the Badlands' Oligocene deposits.

Over 15 excavation seasons, researchers carefully removed the sediment surrounding the remains. They eventually recovered more than 19,000 fossils representing a surprisingly diverse prehistoric ecosystem.

What was buried beneath the Badlands?

Among the discoveries were hornless prehistoric rhinos, small horses and huge carnivorous pigs. The mixture of herbivores and predators offered scientists a rare look at an ancient animal community.

But the sheer concentration and condition of the remains revealed something even more intriguing.

Scientists concluded that the site was likely an ancient, dried-up watering hole.

A drought may have brought hundreds of animals together

About 34 million years ago, the region experienced a major drought. As water sources disappeared, animals from different species may have converged around one of the last remaining sources of water.

As conditions worsened, weakened animals became trapped in the muddy ground around the shrinking waterhole. Their remains accumulated at the site, creating the extraordinary fossil record eventually exposed by erosion.

The result was effectively a snapshot of an ancient ecosystem — preserving evidence of drought, animal stress, survival and death in one location.

Why the discovery matters

Ancient watering holes can provide scientists with important clues about how ecosystems responded to environmental changes. Fossil concentrations such as this one allow researchers to examine how animals behaved under extreme conditions and how climate shifts affected prehistoric landscapes.

The Badlands discovery also demonstrates the role erosion plays in paleontology. The same geological forces that slowly expose fossils can reveal pieces of Earth's history that remained hidden for millions of years.

Today, fossils recovered from the site continue to be studied, helping researchers understand the environment and animals that existed in the region tens of millions of years ago.

Perhaps the most remarkable part of the story is how it began. There was no major scientific expedition at the start — just two hikers paying attention to what was beneath their feet.

Gasman and Carney's decision to report the bones rather than disturb them opened the door to one of the region's significant citizen-led fossil discoveries.

The Big Pig Dig is a reminder that sometimes, a seemingly ordinary walk can lead straight into an extraordinary chapter of Earth's history.