US Open poll

[kissingdaylight]

I'm trying to prove a point to my dad. Do you know where the US Open is played? (Do not google or wikipedia before answering. Just go by what you already know.) If you do not know the answer to any or all questions, please answer "don't know" instead of just not filling out the poll because then only people who know the answer(s) will fill out the poll and it won't be accurate at all. (He thinks people know this, I think they definitely do not.)

The US Open is played in what...
Poll US Open