How much flood risk does Big Horn County actually carry?
Big Horn County lands at the 52.4th percentile of FEMA's National Risk Index for flooding, "Relatively Low" territory — below the national norm for flood hazard — with the hazard driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about once every 1 years. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Who actually carries the flood insurance FEMA requires
3.9% of the homes FEMA requires to carry flood insurance in Big Horn County — those inside the mapped Special Flood Hazard Area — actually have a policy in force: 10 policies against 257 mandated structures, which means a meaningful share of legally-required coverage simply isn't there. Across all residential structures in Big Horn County, not just the ones FEMA mandates, 0.3% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Where Big Horn County ranks
Big Horn County sits at rank 1561 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 2276 of 3144 by population (1 is biggest). About 12,084 people live in Big Horn County, Wyoming, spread over 3,136.957 square miles.
Your street may differ from Big Horn County's average
16 of Big Horn County's 6,501 residential structures carry flood coverage of some kind, per FEMA's latest count — useful context, not a substitute for checking one parcel.
More on how this number was built
The methodology guide shows exactly which FEMA and Census tables feed Big Horn County's numbers. The guide to what the Special Flood Hazard Area actually means explains why the mandatory-insurance rule exists and who it applies to.