On average, a 10″ snapping turtle is 20 years old with growth rates slowing more as they get larger.
The giant ones that some people wrongly pick up by their tail are generally over 50 years old. We see a ton of this on the banks of Pool 4 when they become active again in early Summer/Spring. If I see a large one on the road, I pull over and help it across. 2 years ago one got angry about being prodded to move and decided to destroy my favorite morel stick (an old aluminum ski pole).
It’s an easy pass on me for eating them in current times due to contamination and how cool it is to see the giant ones that are decades old. The ones I did eat in my younger years at an uncle’s house were always rolled in a little flour and fried, before being set in the oven on a tray as was mentioned above.