Jeans and shirt for men, and certainly a Stetson is appropriate. The blazer is sort of dependent upon the August weather in Vacaville, which is unpredictable. Ladies can dress up as much or as little as they like, and I am hearing a whole range as to what they plan to wear. The theme was chosen with the hope that we could make everyone happy. I think it's hard to go wrong with whatever you choose, just come ready to have a good time!