California Real-time Forecast of Earthquake Hazard in the Next 24 Hours
This is a time-dependent map giving the probability of strong shaking at any location in California within the next 24-hours. For this purpose, “strong shaking” is defined as the level of shaking that throws objects off shelves.
http://pasadena.wr.usgs.gov/step/

Earthquake Processes - Cascadia Subduction Zone: The eastward-moving Juan de Fuca tectonic plate meets the westward moving North American plate at the Cascadia Subduction Zone off the west coast of Canada and the U.S.A.
http://www.pgc.nrcan.gc.ca/geodyn/cascadia.htm

Western Region Geologic Information
USGS earth science web pages for the Western U.S.
http://wrgis.wr.usgs.gov

Pacific Northwest geologic mapping and urban hazards
Geologic Mapping in Oregon and Washington Pacific Northwest Urban Corridor
http://geology.wr.usgs.gov/wgmt/pacnw/pnwmap.html

Earthquake 1700 - This earthquake occurred on the Cascadia Fault, the boundary between the North American and Juan de Fuca plates. This type of large earthquake is now known as a megathrust earthquake.
http://www.pgc.nrcan.gc.ca/seismo/hist/1700.htm

Cascadia PaleoHomepage provides information on the geology and paleontology of the Northwest United States and Coastal Western Canada.
http://www.cnw.com/~mstern/

Oregon Department of Geology and Mineral Industries
http://www.oregongeology.com/

The San Andreas Fault
http://pubs.usgs.gov/gip/earthq3/contents.html

GEOTHERMAL ENERGY FROM THE CASCADES
http://www.willamette.edu/~jhook/geotherm.htm

Mount St. Helens Updates: Special Conditions & Recreation Information
http://www.fs.fed.us/gpnf/recreation/current-conditions/special.shtml

Mount St. Helens Seismicity Information
http://www.geophys.washington.edu/SEIS/PNSN/HELENS/

Japanese shipwreck adds to evidence of great Cascadia earthquake in 1700
http://www.washington.edu/newsroom/news/2003archive/10-03archive/k103103a.html

The Cascades Mountaineers is a Central Oregon mountaineering club that sponsors outings and informational programs throughout the year. Our activities range from alpine ascents and winter mountaineering to rock climbing.
http://www.cascadesmountaineers.org/

Virtual Cascades
Experience a virtual mountain adventure among the Pacific Northwest Cascades where a spine of glaciated volcanic summits crowns the western regions of Oregon, Washington, northern California and Canada. VirtualCascades.com features vivid mountain photography, virtual climbs, live wilderness web cameras, links to top mountain web sites, and much more.
http://www.geocities.com/Yosemite/2483/index.htm

Terranes of the North Cascades Chelan Mountains Terrane
http://wrgis.wr.usgs.gov/docs/parks/noca/t5chelanmtn.html

National Weather Service Cascades Range Elevation Information
http://nimbo.wrh.noaa.gov/Portland/cascadeselev.html

Washington State Rockhounding
http://www.washington-state-rockhounding.info/

West Coast Mining - Agate, Picture Jasper, Opal
http://www.wcmining.com/

Collecting Oregon Coast Agates
http://www.geocities.com/SouthBeach/Coast/8385/

The Oregon Department of Geology
Fossils - Learn more about Oregon's geology
http://www.oregongeology.com/learnmore/fossils.HTM

The Cascadia Subduction Zone: The Juan de Fuca and Gorda Plates
http://www.snowcrest.net/freemanl/siskiyou/cascadia/cascadia.htm

Juan de Fuca Volcanics
http://vulcan.wr.usgs.gov/Volcanoes/JuanDeFucaRidge/description_juan_de_fuca.html

Geothermal Energy and Hydrothermal Activity Fumaroles, Hot Springs, Geysers
http://vulcan.wr.usgs.gov/Glossary/ThermalActivity/description_thermal_activity.html

Cascade Volcano Information USGS Cascades Volcano Observatory
Locations and 4,000 year Eruption Summary
http://www.geophys.washington.edu/SEIS/PNSN/INFO_GENERAL/volcanoes.html

Geologic map of Washington
http://students.washington.edu/gwyneth/WAGeolMap.gif

Cascade Range Volcanoes and Volcanics - Maps and Graphics, etc.
http://vulcan.wr.usgs.gov/Volcanoes/Cascades/Graphics/framework2.html
Pacific Marine Environmental Laboratory Vents Program
Researching the effects of underwater hydrothermal venting systems
http://www.pmel.noaa.gov/vents/index.html

Ancient supercontinent of "Columbia" proposed
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1892000/1892869.stm

New Version of Ancient Supercontinent
Geologists working together from around the globe have put together an ancient supercontinent, far older than anything previously suggested. The giant landmass, which they are calling Columbia, would have covered the entire Earth more than one and a half billion years ago.

Above image: Illustration of what the proposed supercontinent Columbia may have looked like, compared to Pangea. Courtesy BBC Online.

Professor John Rogers of the University of North Carolina, the lead researcher, was behind the name for the newly proposed landmass. "I named the supercontinent Columbia because some of the best evidence for its existence is in the Columbia River region of western North America," he said.
http://www.spacedaily.com/news/tectonics-02b.html

Evolution: Pacific Northwest region - Notable Fossil Finds
http://www.pbs.org/wgbh/evolution/local/northwest.html