A new study from Portland State University suggests that some of the Mountain West’s most famous glaciers do not qualify as glaciers anymore. This study defines a glacier as being present for more than 20 years, having an area of at least two football fields (or 0.01 square kilometers), and showing signs of movement. Without these, it’s just a perennial snowpack or a pile of rocks. “If we saw crevasses, then we knew it was moving because cracks develop when the ice stresses and strains, said Andrew Fountain, professor emeritus at the university and one of the study’s authors. “Even though the glaciers might have snow, the one that doesn't move is a snow patch or an ice patch, and the other with crevasses is by definition a glacier.”