When I was a kid, living in Minnesota, we got a lot of snow. Seems like we don't get as much anymore.
Anyway, at that time, instead of using what I have pictured, I used a coyote tail on a stick. Same purpose.
In deep snow, predators are much like people. They prefer to walk, as much as possible, in the easiest places. One of those places is where they have walked before!!!!!
So, being poor, meaning not having a snowmobile, I used to walk the snowmobile trails, looking for where coyote and fox crossed the trail. Then it was a simple matter to go up the predator's trail (where he/she came from) a ways and watch for a tight spot
(a spot where the predator walked between some brush or trees, etc.
Approach carefully. Take out the paddle (homemade) or shovel or bucket or whatever, and, being very very careful not to disturb the track, dig a tunnel underneath the track. Immediately below that track place a trap. In those days for coyotes I used Victor #14 jumps, and for fox I used Victor #12 jumps if I had them, or # 2 if I didn't. Always wired to a drag (stick found nearby so I didn't have to carry so much).
Then, using the paddle, place back the snow dug out. Make sure you leave a space where the trap is though. You don't want to put snow on the trap. Here is where the tail, or the tool shown in the photo comes into play.
Carefully, ever so carefully, brush out the disturbance in he snow so that it looks like nothing was ever there next to the track. And then, being very careful, go back aways and bring some snow back up to fill in your own tracks for about 5- 10 feet from the animal track. And then very carefully brush those tracks out as well so it looks like you were never there.
So, that when you leave that set, it appears that nothing at all was changed.
This set will catch even the most cagey of coyotes and fox.
I was so good at it that I had to resort to using some sort of marking on a tree to remember where I had placed the trap in the event I didn't catch anything. Colored thumbtacks seemed to work well.
Patience is the key. Animals make rounds and they eventually come back. I have had traps out for as long as 3 weeks and through a snow or two, where there were just dimples in the snow for old tracks, and caught coyotes in this set.
The reason I say a tight spot is because later on I used snares. But I still used the tail and paddle to fill in my tracks for at least 10 feet from the snare. You don't want any disturbance bothering the animal when they come through. If there is something they don't like, you will see where they skirted around your trap and just kept right on going, or, sometimes they will walk right up to it, and turn around and go back!!!!!!
Later on when I got a car I used to drive the backroads looking for crossings. Make sure you walk far enough from the road so that nobody sees the animal if you catch one, especially if you hung a snare.