You'd be surprised. I live in upper Washington state and some of our produce does come from Mexico.
Produce is seasonal. On the West Coast the sources follow the weather, starting in Baja and "moving" northward through SoCal, NorCal, Oregon, and Washington (over-simplifying some). Using asparagus, which my Dad raised, along about it would probably be coming from Baja and the Inyo Valley. Come late March, it would be coming from the northern San Joaquin and southern Sacramento Valleys.
Baked goods gets more complicated. Some bread type items are from a Mexican firm, Bimbo. This is because Bimbo bought a large part of Wonder, which means the actual products are baked in America.
I know this sounds like a joke, because of the company name, but it's true.