Terry--
Don't worry--the only way to make a pond non-animal-friendly is to put barbed wire around it.
Pondboss is an all-but-definitive reference, and everybody there will tell you to find out who the best local pondbuilder is and get a consult. I started with the County Extension Service, by the way, which came in and did a soil test and discussed our plans with us.
The fact that you have this on the build-it-yourself forum is worrisome, especially if you're thinking about doing it with a CUT. Mighty unlikely, unless all you're going to do is scoop out a bowl (and even then)--thus maybe the reason for the absence of threads. Pond building usually requires moving LOTS of dirt, digging a keyway for a dam, compacting clay, etc.--think highway-construction equipment; our 3/4-ac. pond was built with a trackhoe, Komatsu, and sheepsfoot compactor (with a CUT to do the seeding). If you can rent and operate a medium-to-large dozer, then you have a chance; however, there will be pressure to get it done, and you might end up sitting in a fililng-up mudhole trying to put a track back on.
The good news is, there's excellent bang for the buck in getting the work done professionally, the land can be sculpted if necessary, it doesn't take long at all, and there is excellent property-value improvement.
Good luck!
