A rancher made a historic and potentially dangerous discovery Tuesday in his pigpen.

The rancher found what was determined to be a military grade mortar dated between 1940 and 1960, according to Placer County sheriff’s officials.

The explosives unit verified the mortar was still intact and a decision to call explosive units from Beale Air Force Base was made to come and place a counter-charge on the mortar.

The mortar was detonated and all of it was caught on video, courtesy of Placer County Sheriff’s Office.