I know its a little late, but thanks for the good advice, Mongo and Tanman..
We were able to tow the travel trailers out of the yard with no problem, using 4 wheel low gear, as the weight was distributed over 8 wheels. The pickup camper with all its weight supported by only 4 wheels, sank right thru the root layer..
It kept 4 of us busy the whole afternoon. The following is a list of what we tried over roughly 5 hours and 2 cases of beer. Any one of them might work in different conditions.
First We jammed 6 ft long carpet strips under the wheels
Then we tried to tow it out with a single pickup
Then we tried with two pickups
Then we tried a 1 ton chain hoist
Then a neighbors small tractor
Then Good Sams
Finally the 12,000 lb winch
The one thing we didn't try was shown on a you tube video, where a guy in Oklahoma, who had sunk in up to his axles, used ratchet tie down straps to fasten a short 2x4 section to each of his tires and just drove on out!!! ...
In time the story will be retold over a few drinks and we'll get lots of good laughs out of it.. We'll also be a lot more careful the next time around.
I keep thinking of the saying that being experienced is the result of learning from the bad decisions we have made..
Hope you all have great season and a safe one.