Maps from the Coastal Zone Atlases, Dept. of Ecology 1978-80, show a total of 71 miles of recently active landslides and 65 miles of dormant slides. Many more unmapped slides exist along Puget Sound, hidden under trees, shrubs, or eroded materials.
Landslides can range in size from tiny to the size of subdivisions.
Notable examples of large slides occur at Ledgewood Beach on Whidbey Island, along Perkins Lane in Seattle, and the vicinity of Hunter's Point near Olympia. Slides along Puget Sound bluffs are caused by a number of factors. A mix of gravity, geology, weather, water, and development often combine to create slides. Slides Gravity Steep slopes and bluffs are more prone to slides. Weather Most slides occur during or after heavy rains, from January through March.