Custom Nav Menu Wordpress

I want to do something like this: xxxx.com/atlanta xxxx.com/newyork xxxx.com/florida Or something like that. I would like the nav menu to change for each area so that: xxxx.com/atlanta would have topics such as: atlanta city parks, atlanta firestations, etc. When you go to: xxx.com/newyork you would have topics such as: new york city parks, new york firestations, etc. I am using Thesis theme and wordpress. I need ...