This has been beaten to death many times before, but here goes, one more time. For climate statistics, the most user-friendly site is
Weatherbase . You can also go to the Western Regional Climate Center site Climate Data Summaries site (
Western U.S. Climate Historical Summaries ) to research, but it is not quite as user-friendly as Weatherbase.
Now, here's the deal: Late fall and early winter (i.e., November and December) are generally low precipitation months in most of Colorado. The bigger ski areas have invested in lots of snowmaking equipment over the years after having a number of Thanksgiving and Christmas holiday seasons with little snow on the ground. The snowiest months in Colorado are February through early April.
The northern mountains of the state tend to be favored with more likely early winter snowfall (December) than do the southern mountains--Steamboat is a good example of this. Because of Colorado's inland continental location, the weather from year-to-year is highly variable. Some years see lots of early season snow, some years none. Based on what is typical, the higher elevation areas of the northern part of the state west of the Continental Divide would statistically offer the best chance of snow on the ground and actual falling snow during December--but there are no guarantees.
A note to the moderators: Why don't you make a Colorado climate and weather subforum, with stickies for the web sites noted herein? It would save having the same questions asked over and over, and having to post the same website links time and again.