I live in Denver but spend a lot of time skiing around 11k feet, maybe the higher elevation means more radiation.
Aside: I'm surprised you got a TPMS programming tool instead of a set of steelies. Big wheels? Multiple winter vehicles?
Interestingly enough, average background radiation is actually the highest in the US exactly where you are[0] and I've seen comments (on a few websites talking about it) ranging from "the Rockies are loaded in Uranium" to "what about the Rocky Flats nuclear weapons site". Perhaps you're exactly in the right place to be an advocate for ECC :)