Grand Coulee Dam
https://www.facebook.com/100003694163721/videos/340579511057631/
I called the casino in town to see if the locals wanted to talk. Woman said town is kind of freaked out many 911 calls. No one has been told. Rumors floating around town are the gun range
Best guess on muzzle flash locations
Looks like top of hill origination from this tower station
Offlimits area