I have a small lake that I have trapped off and on for a few years when the owner contacts me for plugged culverts. I have probably taken 10-12 over 3 seasons, but have not trapped this spot in at least 2 seasonS. My first check on Tuesday I had 1 decent sized beaver in a foothold with a drowning setup and 1 other sprung foothold. That trap had a pile of fresh mud directly on top of the trap in front of my castor mound. I reset both traps using the mud they provided and also mud from a castor mound they made near by, and when checking yesterday, one trap was undisturbed, the other was sprung again, same as previous day. I always set for a front foot catch and very seldom end up with back-foot catches, but I think that I am going to have to adjust these sets because of the way they are springing my current setups. Do you think setting for the back foot in this case is my best option to fool these beavers? My feeling is that setting the traps 16"-18" away from shore should keep them from being plugged with mud and catch the beaver by the back foot when they stand up and begin to smash my castor mound.

Any Advice?

On a spill way I always set for a back foot catch. That is how my mentor taught me. He said always, always, always set for a back foot catch. I have success that way but I am going to start setting for front foot in certain circumstances because I read people doing it on here with success. In your circumstance this should help. The 18” should work but that can vary depending on the size beaver that are left.

How are you setting for the front foot? There's two schools of thought I like on this, the super shallow where you barely have any water over the pan, or the countersink method so the trap can't be belly fired.

I set for front foot with trap in probably 1"-3" of water, in a depression I make with my boot so is level and not tilted front to back with the contour of the shoreline.

Try that castor mound with a 330 set up

Reset the plugged trap and add a trap for a back foot catch. The beaver is going there.

Use a set other than a lured castor mound.