Blog · October 14, 2026 · Wyoming
Big Horn County Flood Zone Map in Wyoming
FEMA's free flood maps and the Big Horn County parcel viewer, used together for property near Basin.
Main page: Big Horn County, WY GIS & Parcel Viewer (official map link, Big Horn County facts and neighboring maps).
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Is that lot in Greybull in a flood zone? The Big Horn County flood zone map answer comes from FEMA, and it is free to look up. You can check it yourself for any Greybull address in a few minutes.
Next: FEMA's search tool, the zone labels you'll see for Big Horn County, and how the parcel record confirms which tract you're on.
Look up the Big Horn County flood zone map step by step
Start at the FEMA Flood Map Service Center and enter the property address in Byron or anywhere else in the county. The site returns the effective Flood Insurance Rate Map (FIRM) panel covering that Byron location, which you can view or download. For an irregular lot near Frannie, try FEMA's National Flood Hazard Layer viewer, which shows how much of a county parcel sits inside the zone. Switch to the Big Horn County parcel viewer and find the same tract around Frannie. The Big Horn County record gives the parcel number and legal description that an insurer or lender near Byron may ask for.
The county map you'll pair it with
Big Horn County publishes its parcels on the Big Horn County parcel viewer, free to use for a lot in Byron or a tract around Burlington. Most people find their Big Horn County tract fastest by searching an address in Burlington, then clicking the outline. Our Big Horn County, WY page keeps the official link and the maps next door to Burlington in one place.
Near the Big Horn County line
Big Horn County borders Big Horn County, MT, Carbon County, MT, Johnson County, Park County, and Sheridan County, and each keeps its own parcel map and records. Every map bordering Big Horn County is listed on our Wyoming directory.
Deeds and plats behind the Big Horn County map
Deeds and plats behind the Big Horn County map are kept by the county's recording office; the official Big Horn County website names which office that is. Copy the parcel number and legal description from the county record before you request a deed for land near Frannie.
What the flood zone letters mean
Any Big Horn County parcel shaded as Zone A, AE, AH or AO sits in what FEMA calls a Special Flood Hazard Area, land with a 1-percent chance of flooding in any given year (the base or 100-year flood). A surveyor working near Byron uses the base flood elevation printed for AE zones; unnumbered A zones do not have one. Land near Frannie in shaded X (Zone B on older maps) is moderate risk, between the 1-percent and 0.2-percent annual chance lines. Clear, unshaded X near Byron is outside the 500-year floodplain.
Unmapped creeks in Big Horn County
A creek near Frannie that shows no detailed zone, which is why it is worth walking the ground after a heavy rain.
Flood insurance and building rules in Big Horn County
The zone shows up again when a loan on a house near Frannie is underwritten. If a house near Frannie falls inside an A or V zone and secures a loan from a federally regulated or insured lender, flood insurance is mandatory; that applies where the local government around Frannie is in the National Flood Insurance Program. In Zone X near Byron, federal rules do not require a policy, though a lender in Wyoming can still ask for it. If a building near Frannie sits above the flood line, FEMA's LOMA process allows a review; a surveyor near Frannie can supply the elevation data. Building or filling inside a mapped zone near Byron frequently requires a permit and an elevation check; the county floodplain administrator can say what applies.
The lay of the land around Basin
Basin is the county seat, and Burlington, Byron, Cowley, and Deaver are among the other towns on the county map. Smaller places such as Hyattville, Shell, and Emblem appear on the county map as little clusters of lots. Roughly 3,137 square miles of land and about 12,018 residents (2023 estimate) make up Big Horn County. Beyond the town lots in Cowley, expect big rural parcels across the county. With a founding date of 1890, Big Horn County has long chains of title on some rural tracts.
Big Horn County flood zones questions
Is my Burlington address in a flood zone?
FEMA's free map service covers Big Horn County: enter the address or pan to the tract around Frannie, then note the zone label.
What if FEMA's map is wrong about my house near Frannie?
An owner near Frannie can request a Letter of Map Amendment from FEMA with elevation data, most frequently from a licensed surveyor.
Who prepares an elevation certificate for a house in Burlington?
A licensed surveyor or engineer prepares it, and the building office serving Burlington may already have one on file for newer construction.
Can I build in a flood zone in Big Horn County?
Often, but local floodplain rules apply; ask the county or town building office in Burlington before you buy.
Is there a floodplain layer in the Big Horn County parcel viewer?
Check the layer list in the Big Horn County parcel viewer; if Big Horn County includes a floodplain layer, confirm the zone on FEMA's map anyway.
What is a base flood elevation for a Big Horn County property?
Near Frannie, the base flood elevation marks how high the 100-year flood is expected to rise, and a surveyor compares the building near Burlington to it.
Open the official Big Horn County, WY parcel map Big Horn County in the Platbookmapper directory
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey, especially for fences, setbacks, or boundary disputes.