Even two weeks after it ripped big, the evidence of the 3-2-07 large natural avalanche in the generally east facing northern branch of Shumway Canyon is Quite impressive.  The powder/hard slab avalanche ran a bit over 3000 vertical feet and delivered an explosive air-blast to many acres of deciduous forest in the Wellsville Mountain Wilderness.

Using Google Earth, I was able to estimate the crown length at around 3/4s of a mile and a running distance of  around 1.4 miles!  Even after a couple weeks and several days of hot and relentless sunshine, the impressive crown was well over two meters deep where it pulled out at the cornice line. The slab probably ranged from 2 to 6 feet deep when it ran, but parts of the crown appeared to be closer to 12' deep... In the exceptional heat today, the shallow bed surface became dangerously moist and softened by prolonged exposure to direct sun.  I turned tail and retreated within a couple hundred feet of the crown after I triggered the second heart-stopping whoomfing noise and sank through moist rotten snow clear to the ground in a couple places.  The avalanche clearly stepped down into a basal layer consisting of sugary depth hoar near the ground.

This is looking down at a big southward bend in the runout track at an elevation of about 6300'.  An explosive air-blast jumped over the ridge at this bend and wrecked havoc on numerous mature trees on the other side.  The avalanche continued down-canyon past the bend for another ~600 vertical feet, raking out the larger, more brittle trees and leaving thousands of young whips uniformly pointing downhill.

The air-blast which jumped the ridge at the big bend in the path sheared off dozens of slow-growing big-tooth maples leaving fresh stumps ranging from a foot to around 25' tall.

Its difficult to describe the extensiveness of the forest destruction. A tangled mess of mangled trees made traveling rather difficult.  Notice the large fir (~60') in the background is missing several branches from high on its profile.  The meadows below were littered with needles and shattered branches for hundreds of feet.  It looked like a tornado passed though the area, or like it was hit by a powerful explosion.

This is the far northern flank of the crown.