Biodiesel is available nationwide. It can be purchased directly from biodiesel producers and marketers, petroleum distributors, or at various public pumps.

Check these listings:

National Biodiesel Board Buying Biodiesel 
Iowa Soybean Association Where In Iowa Can You Find Soy Biodiesel?

Fast links to further information

National Biodiesel Board at www.biodiesel.org  (Tel: 800-841-5849)
Canadian Renewable Fuels Association Biodiesel Information Centre