Walden, Colorado is the coldest location in the state. But why?

Colorado is home to some of the wildest weather across the United States. After all, the old saying goes “The weather starts east of the Rockies.”  
This raised the question; how does the weather behave in the Rockies?  
Geography can have a direct impact on hyper-local weather. I’ve compiled four of the coldest locations across Colorado, please keep in mind these are the four coldest locations with a weather sensor present. 
Consider Alamosa, Gunnison, Antero Reservoir and Walden. They are all ice boxes.
All of these areas are surrounded by significantly larger peaks. This results in cold air drainage, or denser, cooler air from mountaintops sinks into the valley and collects there.  
The mountains also serve as a barrier blocking any wind, preventing the air from mixing. Think of it like a lake filling with water.
Air in contact with the colder ground cools by conducting heat to the ground. When this cooling process occurs along mountain slopes, the cooling air becomes colder and denser than the air away from the slopes, which causes the cold air to sink downslope.