How 11 feet of snow led to America’s deadliest avalanche near Stevens Pass in 1910

This year’s mountain snowpack fell behind average during the mid-winter 4-week dry spell. Last weekend’s wet and windy weather helped make up some ground, but snow levels rose to around 6000 feet before falling during the following days.

The rain that was soaked up by the snowpack below the snow level increased the weight of the snow, particularly on steeper slopes. This situation raised avalanche danger.

Coincidentally, March 1st marks the date of the nation’s deadliest avalanche in American history that occurred 115 years ago near Stevens Pass, back in 1910.

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What led to America’s deadliest avalanche

In the days leading up to that fateful and tragic day, a lot of snow fell in the region. On one day alone in late February, 11 feet of snow fell. Then the weather turned warmer with rain, adding more weight to all that fresh snow on the slopes.

Along the Great Northern Rail Line, snowplows could not keep up with all that heavy snowfall. Two trains, both bound to Seattle from Spokane, were trapped just beyond the west portal of Stevens Pass rail tunnel at the depot town of Wellington.

Early in the morning of March 1st, a thunderstorm unleashed a massive avalanche from the side of Windy Mountain, sending a wall of snow, a half a mile long and a quarter mile wide, down the slopes. The avalanche plowed through the depot and swept the two trains 150 feet down the hill into the Tye River valley. Ninety-six people were killed. Twenty-three survived.

Avalanches carry tremendous power

If planning to venture into the mountains for fun in the snow, be fully aware of avalanche conditions before you go. Visit the NW Avalanche Center’s web site at nwac.us for all the latest mountain and avalanche forecast conditions, and heed any avalanche warning information. In addition, be sure to use the buddy system and have all the appropriate avalanche gear when heading out into the backcountry.

April 1st is usually when the mountain snowpack reaches its peak. With less than a month to go, more snow is needed to reach the average snowpack that at this time, ranges from about 70 to 90 percent of normal.

The outlook for the rest of this month offers increased odds on cooler than average temperatures and tips the odds to wetter than average conditions. This outlook provides the opportunity for the mountain snowpack to play catch up to average by April 1st, good news for snow enthusiasts, as well as water supply and wildfire managers.

Ted Buehner is the KIRO Newsradio meteorologist. Follow him on X and Bluesky.