First off I bet you are asking what a “Wintering” hole is. It is typically the deepest hole in the area that trout school up in and spend their winter. There are a few factors that make a good wintering hole. Slow current is required so the trout can hold in place. There typically is a fast water top of the hole to bring in food.
I fished this hole 10 times last March. It was new permission and I was really excited. I thought it looked like MONSTER water. I took friends a couple times because I didn’t believe I was doing so poorly. 10 outs….4 anglers total and ZERO trout.
I was looking at the photo this morning. The hole is clearly deep and it is the deepest hole in the area. The current is slow on the deep section.
There is a current section at the top of the hole. I just couldn’t solve the riddle. I put the photo on close up. I looked at the water first. Then I looked at the rock.
My educated guess tells me the HUGE rock face is facing north and west. This is the direction the winds typically come from in the winter here. There is lots of rock exposed . This rock face sucks up all that cold and transfers it too the water. This rock face super cools this hole.
I looked at the shallows and noted the bottom was very silty and thought about that also. If a trout wants to winter it needs food. Invertebrates need a food source to live there. Silty bottom means no food source for the main stay of that trout’s winter menu.

The water is too cold and there is no food.