Three tourists face jail time for vandalizing Joshua Tree National Park in California. The National Park Service said a ranger was patrolling the Jumbo Rocks Campground on August 4 when he noticed fresh yellow paint splatters on buildings and street signs.

Police officers were called and began searching the area. They found a vehicle in which a slingshot was clearly visible and questioned the occupants. The three men, who were visiting from Germany, admitted to shooting at buildings and signs throughout the park using the slingshot and a paintball gun.

“Rangers also learned that at least 11 road signs along Park Boulevard from the Jumbo Rocks campground to the Maze Trailhead, two miles from the park’s west entrance, had been shot with yellow paintballs,” the National Park Service said in a press release.

The three men were issued with federal misdemeanor charges of vandalism, damage or destruction of property and face up to six months in prison and a fine of up to $5,000.

“Defacement or alteration of the NPS landscape, no matter how small, is against the law,” said the acting Chief Ranger of Joshua Tree National Park Jeff Filosa“It impacts the natural environment that millions of people around the world come to enjoy. The park must regularly remove graffiti of all kinds, which takes up time and resources that could be better spent on other priorities.”