Sorry for this generic answer but it is the truth.
When the snow gets deep enough to cover their feed up high to where they can''t get to it. It might start in October or December, it just depends on the year. I know of a herd in Utah that winters at 9500' + just because the wind blows the snow off of the high ridge that they live on and there is feed all winter long.
Like this last winter for example. Where I live here the winter was so mild I never saw any elk come down as usual. In general there are several hundred not far from the house by December/January but they never made it all this year.
In the darkness, the hunter stumbles through the underbrush, making noise and leaving his scent seemingly EVERYWHERE!
Daylight will be here in 30 minutes and he wanted to be in the stand an hour before daylight.
"I know I left that stand RIGHT in this area last night," he mutters under his breath, "but where is it now?"
He traipses back and forth in a zig zag pattern, getting himself overheated and sweaty, but never finding the stand he left there the previous evening – and eventually sits on a...