D'oh! I was commenting about safety when your question was about traction.
I have stuck a 4WD tractor at my farm twice in completely water-saturated ground. Once I was close enough to the county road to pull it out with the winch on my pickup. The other time I had to have my wheat farming tenant pull me out with a REAL tractor.
I have also had to have my tenant pull out a fire truck that was stuck in the sand near the creek. (They were putting out the grass fire that was spreading after my old hay barn suffered an arson incident.)
I have tried to pay that farmer for pulling out stuck things on my property. He says nope! Anybody that does serious work on a farm is going to get stuck sometimes. Helping people get free is just what neighbors do. He has stuck his 240 HP tractor.
I am now finally beyond the "embarrassment stage". Just work hard and work smart.
Now that another boring episode of FishinRod story time is over, on to practical solutions.
If you do get stuck at the bottom of your dam slope, I think you are going to just be "barely" stuck (if it is dry). One option would be to set a land anchor at the top of the dam. Get a tow rope and a snatch block. (Or use a truck winch if you have one.) Set wife with truck driving along the top of the dam 90 degrees to direction of pull on the tractor using the snatch block. That should be enough pull to get a "barely stuck" tractor up the slope. (I only have to pull out a 32HP tractor.)
Good luck on your clearing project. Even if you do have some anxiety about using the tractor, remember the formula: diesel engine HP >>>SetterGuy physical labor!
