Ice makes beaver trapping quite a bit easier in many ways. You are now mobile. You can cross the pond or creek without having to go along the shore. Beavers are also easier to find with ice. Their paths are outlined by bubbles and where they get out of the water is clearly visible with broken ice.

A row of beaver bubbles in the ice
The two techniques mentioned above are the primary methods for locating a beaver under ice. Bubbles are left by beavers whenever they swim under ice. Of course, this will help the trapper tremendously. Once the path of the beaver has been determined, hanging the trap from the ice is next. To keep the 330 conibear away from both the mud at the bottom and the ice, it is best to suspend the trap from the ice. Use two wires and attach them to the springs and to a stick. Until you catch a beaver you only need a small hole.
Each morning, you will have to re-chop the hole to check the trap. This way is convenient because the trap will stay below ice level and not freeze.

Chopping around the stick
Hopefully, you will soon catch a beaver. For this beaver, it took several nights before I was able to snag it.

A successful beaver catch
