Butte-Silver Bow, MT: what USGS's seismic model says

Butte-Silver Bow 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, Butte-Silver Bow ranks above 81% of the 4,875 cities in this dataset for seismic hazard - the 81th percentile.

How Butte-Silver Bow compares

USGS's underlying values for Butte-Silver Bow: 0.19g peak ground acceleration, 0.433g at short period, 0.145g at 1 second. Within Montana alone, Butte-Silver Bow ranks 9 of 19 cities by seismic hazard - the 56th percentile in-state. Butte-Silver Bow has a population of about 35,480.

Retrofit economics for Butte-Silver Bow

A full earthquake retrofit typically runs $5,000-$10,000 nationally (around $7,000 typical), driven mainly by house size and foundation type, not by Montana specifically. California's Earthquake Brace + Bolt grant, which covers a large share of this cost, is a California-only program and does not apply in Montana.

Earthquake insurance for a Butte-Silver Bow home

A Butte-Silver Bow homeowner cannot buy a standalone earthquake policy in most cases - it is added to an existing homeowners policy as an endorsement, so the place to start is a regular home-insurance quote.

Where Butte-Silver Bow's figures come from

Butte-Silver Bow's Category D and every number above trace to USGS's own ASCE 7-16 Design Maps service - see the methodology guide. See the category explainer for what Category D does and doesn't tell you about Butte-Silver Bow.