Brookings's Seismic Design Category, explained

Brookings clears the point where the standard Seismic Design Category tables stop applying - USGS returns no letter here, only a flag that a site-specific study (ASCE 7-16 §11.4.8) is required. Treat that as more severe than any lettered category, not as missing data. That puts Brookings in the 100th percentile nationally for seismic hazard - higher than 100% of the 4,875 US cities USGS was checked against here.

Where Brookings sits in Oregon

The raw figures: peak ground acceleration 1.038g, short-period spectral response 2.196g, 1-second spectral response 1.014g. Among 80 Oregon cities in this dataset, Brookings ranks 1 for seismic hazard, the 100th percentile within the state. About 6,493 people live in Brookings, Oregon.

What a retrofit costs in Brookings

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Oregon. A typical retrofit still runs $5,000-$10,000 nationally, about $7,000 for a common single-family job.

What this means for insurance

Outside California, earthquake coverage is typically sold as an endorsement added to a standard homeowners policy, not a separate product - worth asking about directly when getting a home-insurance quote for a Brookings address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Brookings's numbers. The guide to what a Seismic Design Category actually means covers why a category is never a substitute for an engineer's assessment of one specific house.