As we skinned up the slope we got a large "whumph" and crack that propagated about 75 feet uphill. We dug into the crack and saw it was collapsing on a 1.5cm thick layer of well developed, feathery, surface hoar. This is Bulls-eye information that the snowpack is unstable. We made a video of the snowpit too: http://www.youtube.com/watch?v=NDthVJsSFjE Photo: GNFAC