Here is a list from the Yorkshire Terrier Club of America, an affiliate of the American Kennel Club. You will see that, listed by state, are breeder referrals. Those with an "R" listed are rescues. As you can see most states have lots of rescues, but probably need more homes. I did not see any for Oklahoma though, so maybe you could start one in your state.
Yorkshire Terrier Club of America
http://www.ytca.org/breeder4.html#OK
For information on starting a rescue for Yorkies contact Barbara Meskan;
YorkRescue@aol.com . Her address was found on the American Kennel Website
http://www.akc.org/breeds/rescue.cfm
Working with an established network I think you would find much more doable and not so overwhelming. Good luck with your efforts.
Anyone reading this could check out the rescue groups located in your state and offer foster care. Hopefully, with better breeding and a more educated public we will not need Yorky rescue groups in the future.