I've just started playing Prison Architect and I must say WOWZERS! I've wanted to play a new construction/simulation game for a long time, Civ V suxxors. I built a prison and had it running quite well so I decided to add some max prisoners, what fun! I have one prisoner who is sentenced to 65 years ...

You might want to put a fence all the way around the perimeter of your land. Don't build it right at the edge, there are known bugs with fences right on the edge of the land, build like two or three in from the edge. Fences are free right so there is no reason not to do it. You've got the right idea...