Pretty much goatheads are not limited to AZ and can be found all all the Southwest. CA is also a nasty place for thorns - both on road and trail. I actually don't mind the Goatheads as much as now, because of the drought, Southern CA i now covered with Russian Thistle and those thorns are like tiny little evil needles... may take a day or so for the tire to go mushy but then, in repairing the flat, its not uncommon to twizzer out 5, 10, 15 of those little thorns. Worse you can't find them all, repair the flat and the next day the tire is down again because you missed one (Saturday a friend had that happen to her on the ride not once, twice but three times!). Probably the reason why so many people in the West ride Tubeless tires. I haven't gone that way yet... but am thinking about it.

Funny most people prefer flats in the front tire... I rather have them in the back. A flat front means lost of control which can be scary. Hope you are OK.