Hamilton, MT: what USGS's seismic model says

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Hamilton in Seismic Design Category C: Moderate seismic hazard. Code adds irregular-building restrictions and requires bracing of some nonstructural components (e.g. tall shelving, water heaters) in addition to structural detailing. Rank it against the rest of the country and Hamilton sits at the 73th percentile for seismic hazard among 4,875 US cities.

How Hamilton compares

The raw figures: peak ground acceleration 0.131g, short-period spectral response 0.294g, 1-second spectral response 0.105g. Among 19 Montana cities in this dataset, Hamilton ranks 12 for seismic hazard, the 39th percentile within the state. About 5,383 people live in Hamilton, Montana.

Retrofit economics for Hamilton

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.

Earthquake insurance for a Hamilton home

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 Hamilton address.

More on how this number was built

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