I grew up in NE cali in the sierra nevada mt's, used to hear sonic booms and have low fly by's all the time. The Herlong army depot just across the valley had the largest open pit ammo demos in the us 10k lbs at a time. Even though it was 30 miles away you could clearly see the fire ball and about 40 sec later the boom shook the windows, this was done 10-15 times a day 5 days a week.