I took a little picture taking trip to the fort at Fort Gibson. Yes, it is an actual fort. It was used by the US Army from 1824 to 1890. Jefferson Davis was assigned there in the 1830's. It is a beautiful piece of American history, worth the drive.
You can get opening information about the site here.
The fort at Ft. Gibson.
My! I had no idea the outhouses were that nice back then!