Colorado's snowcapped mountains may be beautiful, but they can also be deadly.
This winter, rock slides may be more dangerous than avalanches, that's according to Eric Billmeyer, an instructor in Geography and Enviromental Studies at the University of Colorado at Colorado Springs.
He points specifically to Waldo Canyon, because it faces south and gets sunshine, even in the winter.
Lots of sun means plenty of melting snow, which seeps into cracks and loosens rock.
Billmeyer said that avalanches would become a concern if heavy spring rains fall on already heavy snowpack.