Explosives normally used in mining or excavation work have been found at Lake Roosevelt NRA in Washington state/NPS

Explosive materials commonly used in mining or excavation work have been discovered at Lake Roosevelt National Recreation Area in Washington state, though authorities don't think there's a risk to the public.

National Park Service officials were notified last Tuesday that explosive material had been found on the west side of the lake, near milepost 243 on state highway 395 north of Kettle Falls, Washington. The material was contained in tubes, about a foot long and several inches wide, labeled "Senatel Magnafrac." The Spokane Bomb Squad responded and destroyed the materials.

Two days later the Park Service was notified that additional tubes were located near Snag Cove Campground. The Spokane Bomb Squad responded again, and destroyed the materials. Local law enforcement believes more of these items may be encountered in or around the water.

"These explosives are used in mining/excavation operations, and require additional materials/actions to explode," a park release said. "These materials do not pose a significant risk to the public, and should not impact recreational use of the lake."

Anyone who finds this material is advised not to touch it, call 911, and to be available to direct responding officers to the location so the materials can be removed. Possession of these items without a license or permit is a criminal offense.

National park rangers are investigating the matter with the Ferry and Stevens county sheriff's offices. If anyone has any information about this material, you're asked to call the Bureau of Alcohol, Tobacco, Firearms and Explosives office in Spokane at 509-324-7866.