You probably already know this, but just in case: The best source for info on lost American racetracks is Allan Brown's book, The History of America's Speedways. You'll also want to keep a lookout for Gordon White's forthcoming book, Lost Racetracks, which is due out in later this year. Brown's book is excellent, and anything by Gordon White is worth having. If you haven't been there already, you'll also want to check out the American racing history group on Yahoo, http://groups.yahoo..../RacingHistory/
. There are a lot of knowledgeable people in that group, including Mr. White and Mr. Brown.