Gallatin County, MT flood risk explained
Flood hazard in Gallatin County sits at the 64.2th national percentile, below the national norm for flood hazard; driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about once every 2 years. County-wide, not parcel-specific: FEMA's real flood-zone map is queried live, never shipped as a download.
Who actually carries the flood insurance FEMA requires
Homes with a federally backed mortgage inside Gallatin County's mapped high-risk flood zone (the Special Flood Hazard Area, or SFHA) are legally required to carry an NFIP flood policy. In practice, 19.7% of them do — 192 active policies against 975 structures FEMA counts in that zone, leaving a real compliance gap. Looking beyond the mandated zone, 0.8% of all residential structures in Gallatin County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Where Gallatin County ranks
Among the 3144 US counties FEMA scores for flood hazard, Gallatin County ranks 1174 — 1 being the highest hazard nationally — and 515 by population among all 3144 counties covered here, where 1 is the largest. About 126,984 people live in Gallatin County, Montana, spread over 2,605.354 square miles.
Checking a specific address in Gallatin County
Across all of Gallatin County's 42,333 residential structures, 323 carry an NFIP policy today — a county-wide count that still can't tell you one address's own mapped zone.
Where Gallatin County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. If you're unsure why any of this insurance requirement exists at all, the SFHA explainer covers it from first principles.