jd1023epro,
You need a spot where the bank on each side is gradual enough that the underside of the tractor does not drag. It would probably be difficult to cross a creek with the MMM attached. You also need a spot where the tractor will have good footing both at the banks and at the creek bed. You don't want it to sink down very much.
This creek thing reminds me of the time I was riding a bus in Costa Rica. We were heading for a white water rafting tour about 2 hours from our cruise ship dock. On the way, we had to cross a different river but the bridge was being worked on. So, with one lane open, the traffic from each direction had to alternate using the bridge. No big deal - we see this all the time in this country as well. So with a slight delay, we proceeded across and on up to our rafting location. After the 2 hour rafting tour, we headed back down the same road to return to the cruise ship. Soon we arrived at the bridge that was still being worked on. Only now, BOTH lanes of the bridge were CLOSED. All the traffic was diverted down the river bank, though the shallow, rocky river, up the other bank and back onto the road. We completed this detour without incident but with a memory that I'll never forget.