DENVER -- Two shooters aiming at the spinning blades of windmills have caused $14,000 in damage to two windmills on Pawnee National Grassland.

The shooting occurred earlier this week and caused extensive damage to the motors of the windmills, the National Forest Service said Thursday.

The windmills are used to generate power for water tanks used by cattle that graze on the grassland.

Anyone who has information about the incident or who knows who is responsible is asked to contact U.S. Forest Service Special Investigator Kim Jones at 970-498-2507.

Recreational shooting is allowed on public land, but it is illegal to shoot in or within 150 yards of a residence, building, campsite, developed recreation site, or occupied area; across or on a National Forest Development Road or body of water; to cause property damage and on other specific areas, that are identified locally.

Violators can be fined up to $5,000 and could serve six months in jail. They must also appear in federal court.

For more information about target shooting in the national forest or on national grassland, please contact the U.S. Forest Service office.