The creeks I have to trap are frozen over to the point, I can walk on them. The other day, I had an otter walk down the middle of the creek. My question is how do I catch this otter???

follow his tracks and see where he goes. I bet you will find a spot you can cover with a 220 somewhere that he goes through.

If the ground is not yet too frozen they can sometime be attracted by a messy dirt hole or above water pocket set in bank. Don't know the above water BG size regs in WI but I have taken many in 160's set in tight enough pinch points. Looks for still open spots in faster water and make bottom edge sets in area. I have tracked otter that have traveled mile or more under the ice from one open spot to another, they are very resourceful at finding air pockets below ice(as water level drop in frozen streams the bank ice drops, some so much they can travel along bank). When ice really gets thick most otter migrate from my headwaters area farther down stream.

Trust me that otter Is heading for open water. And It may never come back to your location. But getting on that track Is the thing to do.

I have 36" 1/2 rebar stakes that I weld a coni clip to so stake can be pushed/pounded into the bottom holding a 220 horizontal(some with flat metal plate foot for rock bottoms w/adjustable height coni clip). Locate small holes in ice where they are using and engage enough if needed to drop trap flat just below ice. A little veg, cattail fluff and or snow to blend opening-killer set when you find an active hole). Even have a couple of holder that have short tabs on stabilizer the drop in the hole and rest on top of the ice for deep water holes w/ no bottom to stake into. I have over 30 styles of homemade BG stabilizers to make quick setting of those really uncommon set opportunities I run across. I don't carry them all with me all the time. I just grab one to make set next trap run. As I run a pretty consistent line I am always trying to get as many good sets per mile(increases the profit w/o extra expense) and this leads to me customizing or creating sets on my line.