CHEYENNE, Wyo. (AP)  A report by the Wyoming chapter of the American Civil Liberties Union contends that the federal Forest Service has engaged in systematic harassment of people who attend Rainbow Family gatherings on public lands.

The A.C.L.U. opened an investigation this summer after a clash on July 3 between members of the Rainbow Family, an informal group of professed hippies and peace activists, and Forest Service law enforcement officers.

About 7,000 members of the group attended its annual gathering this summer, held in the Bridger-Teton National Forest near Big Sandy in western Wyoming.

Forest Service law enforcement officers fired pepper balls  like paint balls but containing a pepper substance  at Rainbow Family members during the incident.