That happened to us in Laughlin, NV a couple of years ago (200 miles from home); wifey was buying a pair of shoes at the Outlet Stores and the Discover card got declined (even though their history should have shown we've been there a half dozen times).
The sales clerk said this has become quite common, and a thirty second security-check phone call from the store fixed it.
Now, however, if we're gonna be traveling, I call ALL of our card companies...
Credit card companies are the new internal passport tracking system, it seems. Couple that with the locator on your phones, traffic cams, and maybe an EZ-Pass transponder, and any normal modern person leaves a wide trail behind him.
Nothing to hide here, but it’s creepy, nonetheless.