Start calling whoever is in charge of your local parks, nature preserves, and botanical gardens. They usually have at least one person who knows this skill. If that doesn't pan out look for some living history events where they reenact earlier times. There's often a plant guru among the reeneactors. If none of these turn up anything start contacting the botany and athropology (thanks, CK!) departments of local colleges and see if anyone there knows anything. This sort of three-pronged search has always worked for me when I've moved somewhere new.

-Blast