Billings, MT: what USGS's seismic model says

Billings carries Seismic Design Category B under USGS's ASCE 7-16 model. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Billings in the 40th percentile nationally for seismic hazard - higher than 40% of the 4,875 US cities USGS was checked against here.

Where Billings sits in Montana

The raw figures: peak ground acceleration 0.063g, short-period spectral response 0.131g, 1-second spectral response 0.057g. Among 19 Montana cities in this dataset, Billings ranks 15 for seismic hazard, the 22th percentile within the state. About 121,483 people live in Billings, Montana.

Bracing and bolting: the actual cost

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

Insuring against this, not just retrofitting

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 Billings address.

More on how this number was built

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