3 year old 3x3 fortress, nothing crazy going on. 296 year old medium world.

Game randomly crashes after a period of time; sometimes up to an hour or two before it crashes, but I can't figure out what's causing it. Been going on since Year 2.

Are there any tools to keep a log of what the game does, that I can reference if I get similar crashes in the future? I've had multiple games now with this kind of random crash, and I can't figure out what it could be. They're never FPS-destroyed forts, but it seems a consistent issue on my system.