Back in the day, I haunted Ascot, Lyons, Orange County, Pomona and Ontario. Maybe another, but I can't remember. Then when we raced, it was Saugus, Mesa Marin in Bakersfield, then up north in Stockton, Roseville and Redding.
My friend raced flat track at Ascot in 1972 on a 250cc Ossa. Going to see the sprint cars there was a hoot. I even took my sister and her daughter there and they had a great time.
I've seen the NHRA at Pomona a few times but never been to those other tracks except Saugus. Went to the USGP of motocross at Carlsbad a few times. That was fun. A 2.2 mile track in a natural canyon and you could bring lawn chairs and an ice chest and sit anywhere. One year they had mountain bikes racing around during intermission. I remember we thought they were crazy. Track was closed to build houses.
Also saw a National mx race at Saddleback in Orange County. Another natural terrain track also closed by housing.