The U.S. Bureau of Land Management has confirmed that it's rescinded permits it granted two weeks ago for a wolf derby on 3 million acres of public land in Idaho. Joe Kraayenbrink, Idaho Falls district manager for the BLM, said the derby sponsors contacted the BLM's Salmon field office last Thursday with "material and substantive" modifications to how the predator derby would be run. The BLM had spent five months on review before issuing the Nov. 13 permit; Kraayenbrink said at this point, "Ambiguity about details of the Derby operation make it difficult to conclusively determine whether an SRP (Special Recreation Permit) is appropriate under our regulations, and if so what terms and conditions would allow BLM to effectively manage and protect public lands and resources." 

You can read the BLM's full announcement here. Derby organizers said the event will still take place on private land, as it did last year. No wolves were killed last year, but participants killed 21 coyotes.