LINCOLN, Neb. (AP) — Some western Nebraska law enforcement officials are cheering a new state lawsuit that seeks to thwart Colorado’s legalization of marijuana, even as Colorado vows to fight it in court.

The petition filed by Nebraska and Oklahoma asks the U.S. Supreme Court to invalidate Colorado’s Amendment 64, the legalization measure approved by voters in 2012.

Sidney police chief B.J. Wilkinson says he hopes the lawsuit draws attention to the frustrations of sheriff and police departments in Colorado’s border states, where marijuana remains illegal. Wilkinson says the amounts of marijuana found on people in Sidney are generally small, but the number of users has increased the workload for his department.

Law enforcement officials in Cheyenne, Deuel, Keith and Scotts Bluff counties have all said legalization in Colorado has affected their work.