LAS VEGAS (AP) — Federal authorities are asking for the public’s help in tracking down two men seen damaging rock formations at a national recreation site in Nevada.

Officials at Lake Mead National Recreation Area said the damage happened during a recent weekend near the Redstone Dune Trail on the north side of the lake. The petrified red dunes found there make it one of the most popular hiking spots in the park.

A video shows two men shoving chunks of sandstone off the edge of an outcropping as a girl screams. Park officials called the behavior appalling, saying the damage can’t be fixed.

“It’s one of my favorite places in the park and they’re up there just destroying it. I don’t understand that,” John Haynes, public information officer at Lake Mead National Recreation Area, told television station KVVU.

Destruction like this at federally protected sites can result in felony charges that come along with potential fines and jail time, Haynes said.