I actually bought it at a store called 42 Saint at Kierland Commons in Scottsdale. They have a big selection of Tankfarm, Salvage, Triple 5 Soul, Diesel and a bunch of other brands I don't remember.
Tankfarm is from Anaheim or something. I know this because they had a prominent mention in OC Weekly long before I cared about clothes. Anyway, the name refers to an oil "tank farm" where the founders used to ride BMX. That's a neat shirt, by the way.
I saw a pretty cool Tankfarm tee in Nordstrom the other day with a print of a squadron of Spitfires (WWII fighter that defended England against Hitler's bombing campaigns). The cotton was soft and the cut was fitted, but they didn't have my size.