Hawthorne Army Depot is located in the west central part of Nevada close to the California state line. It is approximately two hours southeast from Reno on U.S. Highway 95. The facility’s area is 147,000 acres. In addition to on-site facilities at the Fallbrook Naval Weapons Station, the Marine Corps Programs Department operates a 49,000-acre live fire ordnance test facility at Hawthorne, Nev.. The Hawthorne range provides the capability for a full range of state-of-the-art ballistic and functional testing for all weapons from grenades up through the 155 mm Howitzer. Capabilities include full instrument ranges with state-of-the-art radar tracking and video/audio recording equipment. Source of information: GlobalSecurity.org/Hawthorne Army Depot. This area is due east of us and is the direction of the blasts. This to me is a better explanation than sonic booms considering the schedule and frequency of events.