Two spirit squad members were thrown to the turf and riders inside the horse-drawn covered wagon spilled out onto the field, ESPN reported.
The beloved wagon tumbled after the Sooners' fourth touchdown during the second quarter of Oklahoma's 52-14 victory against the Mountaineers. The wagon's body came off the wheel frame and the ponies, named Boomer and Sooner, ran free near the 15-yard line, CNN reported.
A university spokesman said there were no major injuries. In a statement, school officials said they believed uneven weight distribution of riders in the back of the wagon caused the crash.
"Three individuals were evaluated at the stadium and released. All others reported that they were uninjured," school officials said. "Upon initial evaluation, it also appears the ponies are uninjured. Medical staff responded immediately as did the expert horse handlers and veterinarian who staff all games. We are grateful that the injuries were not serious and for the staff members who responded so well."
The Sooner Schooner, which is guided across the field in Norman after every Oklahoma touchdown, has been a fixture at the university since 1964 and became the school's official mascot in 1980, ESPN reported.