"Your mindless destruction of our shared natural resources, our environment and our relationships with friends around the world is unforgivable," musician writes.
Cameron Sholly replaces former Yellowstone Superintendent Dan Wenk less than a week after he said he was being forced out as a possible "punitive action" over the park's bison policies.
Wyoming State Treasurer Mark Gordon launched his campaign in Buffalo on Wednesday, stopped at the Boys And Girls Club's WyoTowne in Casper on Thursday.