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.
So what does your rifle cleaning kit look like? Is it a mess of bore brushes, different solvents and oils? Here may be the answer for you. I’m not going to recommend on how to clean your rifle or shotgun since you should already know that but suggest a way for you to keep all your supplies organized and where you can find them without getting four or five different boxes out to get everything together. And if you are like me and have a half dozen different calibers and...