Boy Scout leaders deliberately destroyed a Jurassic-era rock formation of 200 million years old in the Utah's Goblin Valley State Park.

The group of three leaders were hiking in the surroundings when they decided to film what they thought was a "very good idea" and now they will potentially face felony charges.

The video, in which is possible to see one man pushing and pulling down one of the formations known as "goblins", was posted on YouTube.

"It is not only wrong, but there will be consequences," said spokesman Eugen Swalberg for the State Parks system. "There is a criminal investigation underway."

Glenn Taylor, the man in the video pushing the rock, said yesterday that he thougth he was doing a "civic service" by getting rid of a loose rock.

"We did something right in a wrong way," said Taylor, who afterwards thought he should have called a ranger or authorities for help.