I buy most of my clay and materials at Northeast Ceramic Supply in Troy, NY. However, I live in the Hudson Valley and clay can readily be found in the earth here. A few years ago a group of potters heard about a deposit of Albany Slip Clay, and we went to search for it in a patch of ground in North Albany. We never found the deposit but we had fun, met some interesting folks, and got very muddy!
When my children were young they played in our pond, and realized the bottom was muddy with silt. I told them that they could find clay on the bank, and that if they wanted me to, I would fire the clay in my kiln. They soon found some earthenware clay, dried it in the sun till it was moldable, and made some clay faces from it. After firing, I used some of them, wrought-iron hooks and a slab of oak to make a hanging framework for fireplace tools.