You can go to the AKC site. I'm quite sure there is a conformation club in your area.
American Kennel Club - Club Search and Directory
Do a search for a conformation club and then do one for a breed club in your state and near by states. These clubs usually have contact people who can give you info on breeders. You might want to attend a show or two to meet some of those who show and get to see the dogs.
There is also the Yorkshire Terrier Club of America that you can contact. I think there are a few breeders listed in NY and the states around you. These are starting points. There may be other who know of breeders nearby.
Yorkshire Terrier Club of America