USGS National Seismic Hazard Model values at the county centre, 1,628 sq mi of land.
Very high hazardValues are for the county centroid (42.466, -124.211) at Site Class D, Risk Category II, ASCE 7-16. A specific parcel can differ, mostly because of soil.
Very strong ground shaking is expected over a building’s life. This is at or near a major active fault.
USGS withholds a single overall Seismic Design Category at this location. Under ASCE 7-16 §11.4.8 a site-specific ground-motion study is required at this combination of hazard and site class, so no single letter is reported. That is a requirement for more analysis, never a sign of lower risk.
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