Snoqualmie Valley History A Disturbance in Mount Sis Fault The Snoqualmie Valley Earthquake of 1945

On April 29, 1945, a magnitude 5. 7 earthquake rattled the Snoqualmie Valley, startling local residents including anglers and golfers. J. F. Little and Les Crawford, fishing on Rattlesnake Lake, described the experience as unforgettable, with a whirlpool forming in the lake.

Drug store owner Carl Edgerly, who was golfing nearby, initially thought a bomb had exploded on Mount Si. Fortunately, the quake caused minimal damage, with only one reported injury from falling masonry. The earthquake was centered on the Mount Si fault line, which has a history of seismic activity dating back to 1891, making it a significant geological feature in the region. Despite being less powerful than other notable earthquakes in the Pacific Northwest, this quake remains unique as it was the only one centered in the Snoqualmie Valley. The Mount Si fault line, shaped by millennia of seismic activity, continues to impact the valley's landscape, evidenced by frequent rockfalls.

Local residents have a long history of experiencing the geological consequences of earthquakes, highlighting the ongoing relationship between nature and the community.