It's been 36 years since a civilian got hurt by leftover military munitions at Blue Mountain Recreation Area, but that was one time too many.

The Army National Guard plans a thorough survey this June of about 300 acres to check for unexploded grenades and mortars left over from weapons practice in the area. Troops trained with small arms there from 1947 to 1986, and performed maneuvers through 1992.

"We don't have any records of dud-producing ordnance being fired at Blue Mountain," said Clif Youmans, unexploded ordnance manager at Fort Harrison in Helena. "But we do believe that training types of ordnance could still be there."

That belief stems from a phone call Forest Service spokesman Boyd Hartwig got last year when he started spreading the word about the possibility of old explosives at Blue Mountain.

"We never had a documented incident reported, but the person on the phone said in 1976, there were two girls at a high school party," Hartwig said. "They were playing catch with something, and whatever it was, one of them dropped it and it exploded. One of the girls ended up going to the hospital. It sounded like a 40-millimeter round from an M-203."