Casual is fine ...jeans and button down shirt or polo. No shorts, flip flops and tank tops
Casual but nice. You can go in jeans and nice shirt. Id recommend a polo shirt and some dockers so you don't feel underdressed as there are a lot of people in business suits
Anywhere from country club casual to business attire
Most people dress decently (dresses, collared shirts, even full suits for a lot of the businesspeople who take clients there), but I doubt they'd kick you out for being casual. Just don't walk in covered in mud with holes in your clothes and you should be fine.
I went on a weekend evening and was pretty casually dressed. I suppose as long as you're not walking in there and halter tops and Daisy Dukes, you'd probably be okay.
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