This is called the Cascadia Subduction Zone. According to the Washington State Department of Natural Resources (DNR), earthquakes happen in Washington every day, but most are too small to be felt.

In America, growing fears of a deadly disaster are no longer confined to the Golden State. As earthquakes ... zone. 'Groups of experts have prepared resilience surveys in the states of Washington ...

This is called the Cascadia Subduction Zone. Washington state has the second highest risk in the U.S. of experiencing a large and damaging earthquake because of its geologic setting.