Union County GIS Maps

Union County Maps

The maps below show a few of the county map styles included in our downloads. County packages include map exports in JPEG, PNG, SVG, PDF and GeoTIFF formats plus more than 20 GIS layers for mapping, research and analysis. Available layers include zip codes, area codes, subdivisions, school districts, political boundaries, roads, water features, points of interest and more.

County packages also include historical county demographics, business intelligence, analytical dashboards, AI-ready prompts, markdown files and related reference data. Everything is organized to save hours of manual work collecting current data, cleaning it and joining it together. That makes it easier to move faster on analytics, due diligence, business planning and location research. Paid packages are built for commercial use, but some package contents include source-specific attribution or notice guidance. Review Licensing & Data Source Notices.

Union County Population

Union County had 16,811 residents in 2020. That was 16.8% higher than in 2010. Union County added 4,227 people between 2000 and 2020, which points to steady long-term growth. North Sioux City is the largest city in the county, but it accounts for only about 18% of the total population. The county is fairly spread out, with about 36 people per square mile. Some of the county's most populated postal areas include North Sioux City, Elk Point and Jefferson.

Population Trend in Union County SD

Union County Population per 2000, 2010 and 2020 census counts with a baseline 2030 projection.

Union County Zip Codes

Union County has 4 zip codes. Some of the county's most populated zip codes include North Sioux City (57049), Elk Point (57025) and Jefferson (57038). North Sioux City is the largest zip by population, with about 7,725 residents or 46% of the county total. Together, the three largest zips account for about 74% of all county residents based on 2020 population estimates.

Most Populated Zip Codes in Union County SD

Union County Zip Code populations and trends per most recent census data.

Union County Demographics

Union County has a median age of 40.4, which makes the county a little older than South Dakota overall. About 24.2% of residents are under 18, while 18.9% are 65 or older. That gives the county a fairly even mix of younger families and older adults. The largest age group is 25 to 44 at about 31.3% of the population, which points to a solid working-age base. About 36.5% of adults have a bachelor's degree or higher, above the statewide figure of 31.1%. The county is mostly White by population, though Hispanic, Asian, Black and multiracial residents are also part of the local mix.

Key Demographics for Union County SD

Union County School Districts

Union County is served by 5 public school districts with 4,418 students enrolled in 2024. The largest districts on the county map are Vermillion 13-1, Dakota Valley 61-8 and Elk Point-Jefferson 61-7. Those three districts account for about 77% of public school enrollment in the map area. Total enrollment has stayed fairly steady in recent years, based on district totals from 2017 to 2024.

Largest School Districts by Enrollment in Union County SD

Union County school district enrollment and trends per most recent NCES reporting data.

Union County Housing & Real Estate

Union County has a median home value of $269,500 and a median gross rent of $1,055. About 71% of occupied homes in the county are owner-occupied, so the local housing market leans heavily toward ownership. Home values run above the South Dakota median, while rents come in above the state average. In March 2026, the median listing price was $488,050 and homes spent about 60 days on the market.

Businesses in Union County, SD

Union County has 819 business listings across 298 categories. The largest categories in Union County business listings are Gas Stations (19, 2.3%), Churches & Religious Organizations (18, 2.2%), and Chiropractors (14, 1.7%). The full Union County business listings dataset includes names, categories, addresses and contact details where available. Union County packages also include U.S. Census County Business Patterns data with establishment counts, employment and payroll by industry sector.

Top Business Categories in Union County, SD

Union County Business Listings

Union County business listings sourced from Overture Maps. Includes locations with a high level of confidence.

Union County Basemaps

Union County map and data packages include a set of useful basemaps to help you get started quickly. These include a custom light grey canvas, USGS topo, imagery and other reference layers that make it easier to build clear, meaningful county maps using the included GIS layers, your own data or both. Pre-rendered map tiles for the light grey basemap are included so you can use them offline or host them on your own CDN.

Preview a Live Package Demo

See exactly what is included in a county data package. Inspect how files are organized, the interactive data explorer and how maps and analytics are laid out. The demo loads a real sample package from South Dakota — explore the full structure before you buy.