45 miles is pretty far to drive to san francisco for play-date, but there are two Yorkie groups that meet up in sf about every couple of months.
Yorkshire Terrier Meetup Groups - Yorkshire Terrier Meetups Rick and Jilli at the San Francisco Yorkie Meetup <a href="http://www.JilliDog.com" rel="nofollow">www.JilliDog.com</a> - a set on Flickr Maybe you could start a play date in your area. Post flyers, put ads in papers and so on. Ask the local Vets. if they know anyone else who have Yorkies then leave your name and # for them to call you if they are interested in starting play date. It would really catch on.