I did this once many years ago. While working for a farmer checking the fenceline in his pasture (first time for me in that area), I drove his JD4020, a big tractor, along one side of a bog. The ground looked fine, covered in grass and not really in a low area. The farther I drove, the more the tractor started leaving ruts. I was in 7th gear at half throttle. Looking forward, the ground looked no worse than behind, so I went to full throttle. About 100 yards later, the tractor was sitting on its belly and the ruts were FULL of water!
I went and got the farmer, who instantly realized that he FORGOT to tell me not to go along that area of the fence (duh).
Anyway, we got another one of his big tractors and all the chain and steel cable we could gather at three farms and headed to the beast. Strung out the chain and cable and got the 2nd tractor stuck.
Came back with a 3rd tractor with duals, and with more chain and cable, hooked it in front of the front stuck tractor. Running all three, we got them all out.
That was 30 years ago and I'd bet the ruts are still there.....
Ron