I've been dropping kids off at an upper class public high school in the Midwest for.....geez, 6 out of the last 7 years now. Football isn't HUGE, but it's kind of important. On game days during the season most players wear their jersey (my son did). Some of the girls wore their cheerleader gear, but not the ....ummmm....oh boy, how do I word this.....errrr, the typical "sexy" cheerleader outfit you are picturing in your head. I think there is a "rally" for the Homecoming game, but not 100% sure on that.
"jock" culture, in my experience at least, doesn't exist like it does in TV and film, but most of the high schools I have experience with haven't been that big into sports either.
Honestly this is the most accurate one from my experience, though to add my own words, it was us varsity swimmers that wore lettermen jackets and jock culture didn't really exist and there wasn't really a real social split as people simply stuck with their friend groups. This was at one of the largest public high schools in my area too.
