Colorado is the premier state for ice climbing in the United States. Vail, Rocky Mountain National Park, Ouray/Silverton, and many other venues make up the Colorado Mecca. Our season for ice climbing is October through April. Because of the accessible elevations in RMNP, we start climbing on October and climb all the way through April and into June on the alpine ice climbs (see the Alpine page). Vail and Ouray are best December through early March. All of these areas offer terrain that is suitable for beginners to experts.
Compared to Vail and Ouray, RMNP mostly offers more of a backcountry ice climbing experience with longer approaches, less people (usually), and incredible views. The longer you hike, the less people you will see, and the more virgin the ice will be.