I grew up in the Northern SIerra Nevadas, it was not uncommon to hear 2-3 sonic booms per day and the Sierra Army depot set off 10-15 10,000lbs open pit demos (Every day). They were about 25 miles away and it took about 35 sec between the fire ball and the window ratteling boom. The SR-71's from Mary'sville (I forget the name of the airforce base there in the northeren Sacramento valley) would fly over all the time and caused most of the booms, the others came from f-15's from there and the air guard unit in Klamith Falls Or. And the F-4 wild weasles from the air guard unit in Reno (80 miles south east). They now fly c-130's, I bet they miss the f-4's....
