The day began as overcast and gradually progressed to few. Saw an avalanche above Desolation Lake that broke a couple hundred feet wide. It was unclear if it was human triggered or a natural. All aspects held nice snow excluding due south which had a 1cm breakable crust on top. Noted widespread SH on all aspects above 9000' that was 3-5mm. Dug a pit at 9200' N that consistently produced CTM down 43 cm. Also got a CTM at the 1/5 interface. HS along most of the ridge was 90cm. Solar moistened the southerlies by mid afternoon. Got a large collapse at 9700' on a WSW slope while walking on a well traveled skin track. This reinforces how tracks on a slope may offer a false sense of security and stability.