Snapping turtles are easiest caught on live sunfish or cut bait, using a big hook, wire leaders tied to nylon cord, fished under a float.
They don't like to sun, so trying to trap them with a traditional turtle trap won't work. You can catch them in a large wire trap, baited with some type of meat. Run it often, because they will drown. A cylindrical wire trap, made of welded wire, with a cone-shaped opening, large enough for a big turtle to swim through, works fairly well.
