Washington Obsidian Sources
- List of locations that are sources of obsidian across the state. Also includes a scientific bibliography.
- http://www.sourcecatalog.com/wa/s_wa.html

The Pacific Northwest Seismograph Network
- Based at the University of Washington, the PNSN operates seismograph stations and locates earthquakes in Washington and Oregon and provides information on Pacific Northwest earthquake activity and hazards.
- http://www.pnsn.org/

Washington Division of Geology and Earth Resources
- Part of the Department of Natural Resources. Includes bibliography of Washington geology, news, FAQ, links, and educational resources.
- http://www.dnr.wa.gov/geology/

Pacific Northwest Seismograph Network
- Operates seismograph stations, locates earthquakes in Washington, and disseminates information on regional earthquake and geologic hazard activity.
- http://www.geophys.washington.edu/SEIS/PNSN/

Geologic Information about Washington
- From the USGS, an overview of this region's geology.
- http://wrgis.wr.usgs.gov/docs/stateinfo/WA.html