Sawatch

While descending from the Iowa-Missouri saddle into the Missouri Basin, hiker 1 encountered an area with snow that was slightly deeper than the surrounding terrain. The high winds (gusts to 30 mph) had formed a hard wind slab that required effort to punch through. Until just before the slide there were no signs of crack propagation. The slide was triggered by hiker 1’s attempts to punch through the hard wind slab while descending. The crown formed about 15 feet above hiker 1’s location and propagated 10 feet to skiers left and approximately 150 feet to skiers right. Hiker 1 was carried 20 feet downslope before they were able to get traction on the ground with microspikes and arrest their slide. Hiker 1 then stood up and walked to skiers left out of the path of the avalanche, where they can be seen in the attached photos. The avalanche exposed bare ground in places as shown in the attached photos.

High winds were blowing snow throughout the day, increasing wind loading on the lee side of ridges, with WSW winds of 35 mph and gusts to 65 mph according to Open snow historical weather data.

The snow where the avalanche occurred was 18"-24" in depth with a hard wind slab on the surface.