Mitchell's Seismic Design Category, explained

Mitchell carries Seismic Design Category A under USGS's ASCE 7-16 model. Lowest seismic design category. Building code requires no seismic-specific detailing here beyond ordinary construction practice. That puts Mitchell in the 16th percentile nationally for seismic hazard - higher than 16% of the 4,875 US cities USGS was checked against here.

How Mitchell compares

The raw figures: peak ground acceleration 0.08g, short-period spectral response 0.147g, 1-second spectral response 0.034g. Among 18 South Dakota cities in this dataset, Mitchell ranks 1 for seismic hazard, the 100th percentile within the state. About 15,621 people live in Mitchell, South Dakota.

Retrofit economics for Mitchell

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for South Dakota. 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 Mitchell address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Mitchell'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.