There was a racetrack between Oolitic and Bedford, IN in an area known as the Oolitic bottoms and the Mitchell track just off old Hwy 37 several have told me you can tell right where both tracks were from the air.
I found this little jewel on youtube not sure if it's been posted before. The first 30 seconds is some old NASCAR footage but then it's mostly USAC after that. All from 1958 good video.
http://www.youtube.com/watch?v=D3oBzUikOB8