Blog · October 8, 2026 · South Dakota
Union County Plat Map (South Dakota)
The free official plat map for Union County, how to search it, and what the parcel data does and doesn't tell you about owners, acreage and property lines.
Main page: Union County, SD GIS & Parcel Viewer (official map link, Union County facts and neighboring maps).
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From the lots in Jefferson to the back roads near Richland, the Union County plat map shows who owns what and roughly where the lines fall.
This guide walks through the official link, the kinds of land you'll find around Elk Point, and what to do when the map and the ground don't agree.
Who needs this map
Homesteaders eyeing the country near Richland use acreage and frontage on the record to narrow a long list to a few tracts worth visiting. Vacant-lot hunters working the edges of Elk Point look for parcels with no structures and owners who live out of the area. A small builder looking for spec lots around Elk Point can scan the map for vacant parcels in already-platted subdivisions.
Where to find the official Union County plat map
Parcels from Elk Point to Richland are on the Union County Beacon site, which the county runs on Schneider Geospatial's Beacon platform. In Union County's version, the search page takes an owner, address or parcel ID, and the report page shows the legal description, sales and assessed values. Our Union County, SD page keeps the current link if the official address changes.
What the map covers, from Elk Point to the back roads
The county seat is Elk Point; Alcester, Beresford, Jefferson, and North Sioux City are among the other communities you can zoom to. Unincorporated spots like Dakota Dunes, Richland, and Alsen are worth a look if you want rural acreage near a crossroads community. Organized in 1862, Union County has a long paper trail, and early deeds may cite landmarks that no longer exist. Union County covers about 461 square miles of land; its 2023 population estimate from the Census Bureau was 17,183. Outside Jefferson the parcels open up quickly into farms, timber and small acreage homesites. Watch how parcels line up along the Big Sioux River, Missouri River, and Missouri National Recreational River; waterfront tracts often have odd shapes because the deed follows the water. On the parcel layer, Adams Homestead and Nature Preserve and Union Grove State Park show up as public ground, and the private tracts along their edges are worth checking line by line.
How accurate are Union County, SD property lines?
Zoom in far enough on a lot in Jefferson and you may notice lines crossing driveways or splitting sheds, a normal quirk of tax mapping. South Dakota uses the Public Land Survey System, so rural deeds in Union County often describe land by section, township and range, and you can match the call to the grid on the map. Corner pins, a recorded plat and a South Dakota licensed surveyor beat any line on a screen.
Acreage and vacant lot search
How to work the Union County plat map for open land:
- Scan the imagery around Richland; open fields and woodlots with no driveway stand out right away.
- Build a short list of open parcels around Beresford with owner names and acreage before you make any calls.
- Check that the tract touches a public road; a landlocked lot near Beresford can be hard to finance and build on.
- Assessed values lag the market, but comparing tracts near Richland still shows which ones the county rates higher.
- Ask the local offices serving Beresford about building permits and septic rules before you buy.
The Union County economy in brief
Federal business data for 2022 shows 583 establishments in the county, with health care and social assistance, construction, and professional and technical services at the top of the list. What stands out is machinery manufacturing, utilities, and accommodation (hotels, motels, RV parks and camps): those sectors make up a much larger slice of local businesses than they do nationally. A buyer looking for a cabin lot near North Sioux City may find recreation buyers in the mix too. If you're comparing land near Alcester with land near Jefferson, the local job base is part of the price story.
Where Union County deeds and plats are kept
The map near Elk Point is only as good as the deeds behind it, and those are kept in the county's recording office. Which office that is depends on how South Dakota organizes it, so look it up on the Union County government site before you call. Copy the parcel ID and legal description before you call or visit; recording staff can find a Union County document much faster with them.
Near the county line
If your land is near the edge, check the next county over too: Plymouth County, IA, Sioux County, IA, Woodbury County, IA, Dakota County, NE, and Dixon County, NE border Union County. Use the South Dakota county GIS hub to jump between them.
Frequently asked questions
Do I need an account to use the Union County GIS map?
There's no fee to view the Union County Beacon site. Fees only apply if you order copies of recorded documents for a Union County tract.
How do I look up a property owner in Union County, SD?
Search by address if the lot near Jefferson has one; otherwise click the tract on the map to see the owner of record.
Does the Union County, SD map show flood zones?
Zoning for land near Beresford comes from the local planning office; flood zones are on FEMA's map service if the viewer lacks them.
Where do property lines run on a Union County, SD lot?
For a lot in Beresford, start with the parcel map, then get the recorded plat; a surveyor sets the exact corners.
Open the official Union County, SD parcel map Union 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.