Unmarked hazards exist

Did not dig any profiles and only a few hand pits. 2-4" of low density new snow, sitting on supportable crust 1-3+ cm thick below about 5200 feet. Sitting on dry snow above that elevation. New snow not slabby, except occasional small (< 3') cracks around skies where sitting on dry snow. Seemed to want to sluff where crust thicker and harder. 1 whumpfing collapse as partner skied towards me on SW-facing slope ~ 5350 feet. No drifts, downed trees, or other signs of strong winds. Crust supportable enough to offer dependable turns to trail at 4200 ft, despite thin snow cover and a plethora of unmarked obstacles.