Lewis and Clark County, MT flood risk explained
Flood hazard in Lewis and Clark County sits at the 64.6th 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 1.1 times a year. 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
Out of 897 homes FEMA counts inside Lewis and Clark County's mapped flood zone, 123 carry the flood policy federal law requires there — 13.7% compliance, short of full coverage. Looking beyond the mandated zone, 0.6% of all residential structures in Lewis and Clark County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Where Lewis and Clark County ranks
Among the 3144 US counties FEMA scores for flood hazard, Lewis and Clark County ranks 1162 — 1 being the highest hazard nationally — and 752 by population among all 3144 counties covered here, where 1 is the largest. About 75,129 people live in Lewis and Clark County, Montana, spread over 3,458.38 square miles.
Checking a specific address in Lewis and Clark County
FEMA counts 29,914 residential structures in Lewis and Clark County overall, 176 of them carrying some form of NFIP coverage — but a lender or insurer cares about one parcel, not that county total.
Where Lewis and Clark 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.