Does Belgrade, MT need an earthquake retrofit?

Belgrade carries Seismic Design Category D under USGS's ASCE 7-16 model. High seismic hazard - this is the category most of coastal California, the Pacific Northwest, and other active fault regions fall into. Code mandates significant seismic detailing and restricts irregular structural configurations. This is the category the Brace + Bolt scope (cripple-wall bracing, foundation bolting) is built for. Nationally, Belgrade ranks above 87% of the 4,875 cities in this dataset for seismic hazard - the 87th percentile.

How Belgrade compares

The raw figures: peak ground acceleration 0.371g, short-period spectral response 0.831g, 1-second spectral response 0.248g. Among 19 Montana cities in this dataset, Belgrade ranks 3 for seismic hazard, the 89th percentile within the state. About 12,741 people live in Belgrade, Montana.

What a retrofit costs in Belgrade

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 Belgrade address.

More on how this number was built

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