I haven't seen this topic in a search of the archives. Out of curisity the other day I contacted our state dept. of Agriculture. They are the ones in Oklahoma that licenses dairy farms. I talked to someone in the food saftey division and they were happy to email me a list of licensed dairies in the state. It list the owner of the dairy, the approx. number of milking animals, the mailing address and phone number. Some also had notes attached such as goat dairy, or sheep.
It you are interested it might be worth while to contact the equivalent in your state or such. For instance I found out that there are two cow dairies close at hand and one sheep that I already knew about.