We didn’t have a lot of advanced information on that during our walk, and mostly just asked around town where the “health food” store was. This backfired several times, as we overshot the store (Like in Bandon). However, we discovered that the stores ususally have listings of the coastal markets. I think it would be a good move to research the first town, and then contact that store and ask them about the next towns. Also you might find something on the internet, but why pass up an opportunity to talk to a real person?
The above approach might work with the PCT also!
This trend continues through Northern California, with less frequency of towns. Humboldt and Mendocino have many OG markets.
A hiker named “SQUID” is assembling a DATA BOOK on the American West Coast Trail (see www.thawookie.com for update on his progress), and since he seems to prefer health food stores, I bet his guide will include that info.
Tha Wookie