On our trip to Gatlinburg, we stopped in Athens, TN to see the Mayfield Dairy. It is only 4 miles off the interstate and is free. They make milk and ice cream at the Athens plant. Apparently they only make milk in the Braselton, GA plant and only ice cream at the Birmingham, AL plant.
The best part was that we had to wear hair nets on the tour:
I wish they gave out free samples at the end of the tour, but they don't. You have to buy the ice cream. Catherine enjoyed some pink ice cream (well, a few bites of it):
Sabrina enjoyed some Moose Tracks ice cream: