Here is a link to a PDF file on the USDA dept. ag & markets listing all processors in the country. It's a large file, so download it and you can search for you state/area. http://www.fsis.usda.gov/PDF/MPI_Directory_by_Est_No_Pgs_1_200.pdf
That is a nice source. I noticed the entries in my state were all big operations like Foster Farms (our equivelant to Tyson chicken). WSDA puts out a list as well of approved processors. Just phone the small farm coordinator office and they'll send you a map even with phone numbers.