Dr. Joe,
There are two locations that raise and distill mint oil that I can tell you
about.  One is in Central Oregon located near Madras, Oregon, the other is
the Klamath Basin on the California/Oregon border.  Farm advisors in the
Central Oregon Research and Extension Center,
http://oregonstate.edu/dept/coarc/ 
(541-475-7107) could help you get some contacts, and the Intermountain
Research and Extension Center in Tulelake, CA, (530-667-5117)
http://groups.ucanr.org/intermountain/
and the Klamath Basin Research and Extension Center in Klamath Falls, OR,
(541-883-7131) http://extension.oregonstate.edu/klamath/index.htm
could help locate some contacts here.

I, of course, can help you if these fail to do the job...

Jim Smith
State of Jefferson
Tulelake, CA

****************************************************
* General Information About BEE-L is available at: *
* http://www.honeybeeworld.com/bee-l/default.htm   *
****************************************************