Try your yellow pages under 'Hardwoods'.
I did turn up this list using
http://www.woodfinder.com . . .
Woodcraft - Franklin, TN Franklin TN (32 miles)
Woodcraft - Evansville, IN Evansville IN (119 miles)
Bill Kraemer Veneers, Inc. New Albany IN (145 miles)
Woodcraft - Louisville, KY Louisville KY (145 miles)
Woodcraft - Knoxville, TN Knoxville TN (157 miles)
Colco Fine Woods & Tools Memphis TN (194 miles)
Cedar Creek Hardwoods, Inc. Fredericktown MO (209 miles)
Woodcraft - Pelham, AL Pelham AL (210 miles)
Doug White Hardwoods, Inc Marissa IL (211 miles)
Woodcraft - Roswell, GA Roswell GA (213 miles)
My local Woodcraft stores carry limited sheet stock, but if you strike out in the Yellow Pages, it may be worth a call.