Update, some online searching shows a source (
Seasonal only) for Turmeric rhizomes)
http://www.localharvest.org/custom-gardens-organic-produce-farm-and-working-member-csa-M630They say December for local harvest and you must contact them (call or email)
to get an invitation to the location of their "local harvest store" which is open June through Fall (not clear on when fall ends for them).
Another listing or the same farm is here:
http://buynevada.org/businesses/growers/custom-gardens/They are in Silver Springs, more or less local. They would like to have you make an appointment, not just drive-by shopping. This is partly due to the seasonal nature of their product and partly (I suspect) to keep the traffic down)
Let me know if you do contact them and find Turmeric.