2 questions
Are there a lot of single women in Wyoming and can I smoke a cigarette in a bar there
Single women? Um, no. I'm from Wyoming (and proud of it), but it is definitely not a singles' paradise.
As to smoking in bars, yes you can. I've heard that Laramie (home of UW) has put a ban in place, but the rest of the state is way to conservative for such nonsense.
If you like wide open spaces, beautiful scenery and participating in outdoor activities (hunting, fishing, snowmobiling, skiing) Wyo is a fantastic place. If night clubs are your thing, it probably isn't for you.