Mississippi State Fairgrounds

*The only way to enter is the gate on High St. All other gates are locked *

A great spot for big rigs, especially to be in the heart of downtown Jackson. The lady who answered the phone number listed was not very knowledgeable on the overnight parking but gave me Mike's number (who regularly paroles the area in his f-150) which is (601) 668-4451 . He's super friendly and will tell you where things in the area are, and what not to do.

If you arrive later evening you pay in the coliseum the following morning. If you arrive during regular hours, it wasn't clear if he handles the payment or if you still go into the coliseum.

We were allowed to boondock for free, but otherwise it is full-hookup at $30/night for 30amp or $50/night for 50amp. The state fair is in October, so you may not be able to stay during that time.
There are several long-term rigs, but you wouldn't know it as the sites are tidy and minimalistic.

It's not a glamorous stay, but very safe as there are a couple police vehicles parked in various corners + security cameras, and right across the street from the museums.