Blog · October 14, 2026 · North Dakota
Sioux County Flood Map: checking a property's flood zone
The zone on FEMA's map affects insurance, building and resale near Fort Yates.
Main page: Sioux County, ND GIS & Parcel Viewer (official map link, county facts and neighboring maps).
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Before an offer near Missouri River, look at the Sioux County flood map: a mapped flood zone changes insurance, permits and resale. What this county guide covers: locating a parcel on FEMA's map, reading the zone codes, and matching it with the county parcel viewer, at least around Porcupine.
Checking the Sioux County flood map step by step
If you're looking near Porcupine, the official source is FEMA's Flood Map Service Center: enter the street address, and pick the FIRMette or map view. A tract near Cedar Creek without an address can still be found: pan from the closest town then click the parcel area.
Getting to the right map
Lots and tracts near Porcupine appear on the Sioux County Portico map, a viewer that needs no account. For land near Lake Oahe, enter a street address, an owner's name or a parcel number, then pick the result to center the map on it. For acreage around Solen, save the parcel ID before closing the panel; each records desk in the county asks for it first.
Land on the county line
The county borders Adams County, Emmons County, Grant County, Morton County, and Corson County, SD, and each of those keeps its own parcel map, at least around Solen. Acreage along the edge near Lake Oahe may show up in two county records, so check the adjacent map as well. For land near Lake Oahe, the Platbookmapper state page lists every neighboring county map for North Dakota.
Beyond the mapped zones
Small streams around Fort Yates may not have detailed mapping, so look for water marks and debris lines. Wetlands near Solen can limit building even outside a flood zone; the National Wetlands Inventory mapper shows mapped wetlands.
Zones on the Sioux County flood map
If you're looking near Cannon Ball, zones beginning with A or V mark the Special Flood Hazard Area, which FEMA defines as a 1% annual chance of flooding. For property near Fort Yates, a low-risk label isn't a guarantee: according to FEMA, floods happen outside mapped zones too.
Sections, lots and bearings
North Dakota uses the Public Land Survey System, so rural legal descriptions near Lake Oahe cite section, township and range. Each section is nominally a mile square, about 640 acres, and a township holds 36 of them, though real sections near Cedar Creek vary in size. Write down the legal description for the tract near Cannon Ball when you talk to a surveyor.
Limits of the parcel data
For a tract near Selfridge, acreage on the record is an estimate; only a licensed surveyor sets the real corners on the ground. For a tract near Fort Yates, records update in batches, so a deed recorded last month might lag behind.
Taking the map into the field
Most viewers work in a phone browser, useful out on a road near Cannon Ball, but coverage can be spotty out of town. A screenshot of the parcel near Selfridge with its ID keeps working without signal.
Getting your bearings
Fort Yates holds the county offices, where most land records are kept. Smaller places on the map include Selfridge, Solen, Cannon Ball, and Porcupine, where town lots give way to larger tracts. About 3,643 people live in Sioux County (Census estimate, 2023) across some 1,094 square miles. The county was formed in 1914, which matters when you trace an old farm's title, at least around Solen. Features like Cedar Creek, Missouri River, and Cedar River National Grassland are easy to spot when you zoom out.
Matching the zone to the lot lines
FEMA doesn't draw property lines, so pair it with the Sioux County Portico map to see exactly which lot near Missouri River you're looking at.
Lenders and permits
For acreage around Lake Oahe, an Elevation Certificate from a surveyor helps: it compares the building to the BFE. Building or adding on near Cedar Creek in a mapped zone often needs a floodplain permit; ask the local floodplain administrator before you plan.
A short flood checklist
Out toward Fort Yates, ask the seller about past flood claims before closing; an insurance quote early avoids surprises.
Which office to call
If the acreage or value on a parcel near Lake Oahe looks off go to the Director of Tax Equalization, since that office keeps the assessment data. Zoning, permits and septic questions near Cannon Ball go to planning, building or health offices, and the answer depends on jurisdiction.
Questions about the Sioux County flood map
Can I see flood zones on the Sioux County Portico map?
In most cases, the parcel map near Solen might show FEMA zones, but FEMA's own map is the official source.
Where can I see the county flood map for free near Porcupine?
Usually, search the address near Cannon Ball on FEMA's Flood Map Service Center, which takes a couple of minutes.
What is the difference between Zone A and AE in Sioux County?
For land near Porcupine, an AE zone has a 1% annual chance of flooding and a base flood elevation; unnumbered A zones don't list one.
Can a property in Zone X near Cedar Creek flood?
For property near Fort Yates, shaded X is moderate risk and unshaded X is minimal risk; FEMA notes that a large share of claims come from these areas.
Is the parcel map a survey near Selfridge?
No; boundary questions near Cedar Creek need a licensed surveyor.
Open the official Sioux County, ND parcel map See it 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.