Visitors are seen on camera damaging rock formations at a Nevada recreation site

LAS VEGAS– Federal authorities are asking for the public’s help in locating two men who spotted damaging rock formations at a national recreation area in Nevada.

Lake Mead National Recreation Area officials said the damage occurred over 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 pushing pieces of sandstone off the edge of a cliff as a girl screams. Park officials called the behavior appalling and said the damage cannot be repaired.

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

Such destruction at federally protected sites could result in misdemeanor charges, which carry possible fines and prison sentences, Haynes said.

The Lake Mead National Recreation Area, just outside Las Vegas, covers 6,071 square miles of mountains and desert canyons and attracts approximately 6 million visitors annually. Officials said staffing levels mean park officials often rely on the public to also monitor resources within park boundaries.

Authorities said visitors can use their cellphones to capture videos or photos of suspicious activity if it is safe to do so and to collect any information, such as a license plate number, that could help identify offenders. The National Park Service has a tip line that receives thousands of submissions each year.

“It’s very important to let us know,” Haynes said.

There have been other incidents of vandalism on federal lands in the West in the past decade, with visitors defacing petroglyphs, knocking over rock formations and hammering climbing bolts into ancient petroglyphs.