Depends heavily on the state, union, and the contract. Best case you live in a rural state with a strong union and contract, so your cost of living is low and the pay is high. These states typically build the prisons in rural areas as an employment booster / vote harvester.

Typically the highest uniformed security rank requires only a high school diploma or equivalent - plus seniority, good evals, exam scores, and interview skills. Because it is such an unsavory job of last resort, negligent understaffing is the norm, so you can make six figures even in your first year on volunteer overtime. And most overtime is simply attendance; they require the body more than the workload.

Meanwhile the benefits are outstanding, the time off is criminal, and it's a job that still has a very generous pension provided you beat the odds and live to use it - - because most C/Os eat, drink, and smoke themselves to death by 59. People do beat those odds though. Guys who are brave enough to hire in at 18 or 19 commonly still live at home, so they end up buying their first house at 21 in cash. They'll never have debt in their lives.

In states where they make Taco Bell level wages, no, it is absolutely not worth it.