DNR releases new maps; active faults, other features shown in King & Snohomish counties

Monroe 7.5 minute quad map
The newly released Monroe Quadrangle Map shows the Cherry Valley fault and other features in King and Snohomish counties. Map: Division of Geology and Earth Resources/DNR.

A new map released today by DNR shows the Cherry Valley fault and other potentially active faults of the southern Whidbey Island fault zone in eastern King and southwestern Snohomish counties, an increasingly populated region just east of Seattle. The map also locates the active Cherry Creek fault zone, a subsidiary structure that produced the magnitude 5.2 Duvall earthquake on May 2, 1996.

The geologic map of the Monroe quadrangle is available only online. It is the latest of several 7.5-minute quadrangle maps in a multi-year effort by DNR to document the rock and soil types and many faults, folds, and geomorphic features across Washington State. Partial funding is provided from the USGS National Cooperative Geological Mapping Grant Program. 

DNR’s Geology and Earth Resources Division is working with university, federal, and local researchers to better understand the connection between the Rattlesnake Mountain fault zone in the North Bend area and the southern Whidbey Island fault zone. Knowing the geology of an area can help local governments and residents avoid geologic hazards, locate water and other earth resources, and plan intelligently for the future.

The Washington Division of Geology and Earth Resources, a division of DNR, is Washington State’s geological survey, established in 1890.

This mapping project is a continuation of earlier work to trace earthquake faults in western Washington. All of DNR’s Division of Geology publications are now accessible online – see our Publications List.  See a list of online geologic maps of Washington from all sources.

Find out more geology and earth science information

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