If @Okie4570 ’s size estimate is accurate, it’s not difficult to imagine 18,000 head of dairy cattle in that building or its vicinity. It looks like that lot is about a half section; on any given Saturday in the fall, there are close to 100,000 people in about half that area on OU’s campus, so if you figure that four or five people occupy the same space as one dairy cow, it’s not hard to imagine them having 18,000 cows in or near that building.