We have quite a few military bases, in California. Camp Pendleton, Miramar Naval Air Base, Los Alamitos Naval Air Base, Twenty-nine Palms, Camp Irwin, March Air Field, Edwards Air Force Base, and many more.
I have seen helicopters going up and down the coast, from time to time. Many of those bases, are along the coast. The Marines do desert training in the desert. Duh.
It never occurred to me to get all tinfoil about military exercises. Obama likes to tweak his opponents, and it works.