Rather steamed about it. Weird thing is I have several others set up in the area and those are all untouched, except for the one with a beaver in it that was touched by a beaver, obviously.
I talk to the local cops pretty regularly so I'll mention it to them but I don't think there's any chance I'll get it back. Definitely was a human that took it though cause I staked the chain ring using a wooden pole and you'd have to lift it about 2 feet straight up to get it off without moving the pole, which is exactly what happened. Nothing else in the area was disturbed either, including my stabilizers and guiding sticks.
Update: After checking several times hoping that a critter had indeed just had a bad catch and managed to somehow slip the ring off my stake and would eventually float to the surface somewhere, I changed up my approach and approached the dam from the underside in my kayak with a big flashlight on a dark night. There, just below the dam break stuck between two branches I saw the glisten of the trigger wires. A few minutes of fishing around the area with a crook managed to dislodge it and I pulled it back up to the surface, 40lb beaver in tow.
I double checked my stake afterwords and realized it didn't move unless you pushed it hard in the exact direction that I found the 330, and that if you let up the pressure the weight of branches would immediately snap it back into place giving the illusion it hadn't moved. Long story short I will reconsider how I attach dam break sets if I do more in the future.
Thanks to everyone who weighed in with concern and advice. I'm sure I'll need more in the future.