Along the front range in Colorado there is local roadracing. Second Creek. There used to be another up along I25 North of Denver, once called Mountain View, now called Continental Divide, not to be confused with the one that used to be south of Castle Rock. I think that was a drag strip, and maybe an oval.
I liked those two. Though Second Creek scared me a little.
Otherwise check local motorcycle shops.
Miller and WSBK would be the closest big time racing.