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.
January: Last years Season has ended.Time to start focusing on next year's season. You will need to find out what bucks might still be alive that made it through the last years hunting season. After the hunting season sometimes bucks and does might leave your area and go to another traditional winter yarding area. But they will return to the area around late February early march to spend the rest of their summer there. At this time of year, the use of scouting cameras will be the tool in...