When the flat surface of a glacier is free from rocks, snow and crevasses, it can be very easy to walk on. Exposed surface ice on glaciers partially melts and becomes a reticulated lattice of tiny ice crystals. It lightly crunches beneath your feet as you walk across it. Yet only a few inches beneath this 'rotten ice' the glacier ice is solid, often clear or bluish and hard as only glacier ice can be. All the white in this photo's foreground is 'rotten' glacier ice. There's no snow, but a few feet down there is probably rock hard glacier ice that has not seen the light of day for centuries. Photographer: Bill Eichenlaub