Polk County in central Iowa is anchored by Des Moines and an urban network that includes Ankeny, West Des Moines, Urbandale, Johnston, Altoona, and several adjoining communities. I-35 and I-80 provide the strongest road references, while U.S. 69 and Iowa routes 163, 330, 415, 65, and 17 help locate the northern, eastern, and western parts of the county. Saylorville Reservoir dominates the northwest water map, and the Raccoon and Skunk river systems create separate lowland corridors. High-resolution JPG versions of the supplied county, city, terrain-and-water, and elevation maps can be downloaded in a ZIP near the end of the page. High-resolution map files are available for download in the section below.
The county’s relief is easy to miss on a road map because the metropolitan street network is so prominent. The elevation sheet shows a different picture: lower terrain follows Saylorville Reservoir and several river corridors, while higher ground occupies broad parts of the northern interior and portions of the east. Using large water features together with major roads makes the county much easier to orient.
Table of Contents
Des Moines, I-35, and I-80 anchor the metropolitan road network
Des Moines occupies the southern-central part of the county and blends into West Des Moines, Clive, Urbandale, Pleasant Hill, and other nearby communities. I-80 crosses the county from west to east, while I-35 links the Des Moines area with Ankeny farther north. Their junction provides the clearest large-scale road reference on the general map.
U.S. 69 continues north from the Ankeny side toward Alleman, and Iowa 415 runs near the eastern side of Saylorville Reservoir. Iowa 330 and U.S. 65 form strong references toward Bondurant and Mitchellville in the east, while Iowa 163 extends east from the Pleasant Hill area. Iowa 17 appears along the western side near the Grimes and Polk City area.
Polk City is close to Saylorville Reservoir in the northwest, Johnston lies farther south, and Ankeny occupies the north-central urban area. Altoona and Bondurant provide eastern references, with Mitchellville close to the county’s eastern edge. The map is intended for county-scale orientation rather than live traffic, so current closures and construction should be checked separately.
Des Moines leads the six highlighted cities
The city map ranks Des Moines first with a mapped population of 212,421. Ankeny is second at 72,615, West Des Moines third at 71,083, Urbandale fourth at 46,595, Johnston fifth at 24,384, and Altoona sixth at 21,495. The ranking emphasizes how strongly the county is shaped by a large metropolitan cluster rather than a single isolated city.
Des Moines lies in the southern-central county, West Des Moines in the southwest, and Urbandale with Johnston farther northwest. Ankeny is the major north-central city, while Altoona provides an eastern urban reference. Together, these places show a broad developed belt stretching across the southern and central parts of the county.
The surrounding county labels include Story, Jasper, Madison, Marion, Warren, Boone, and Dallas. Those references help place Polk County within central Iowa and show how the metropolitan area approaches several county boundaries. The northern and northeastern parts remain much less densely urbanized on the map than the Des Moines-centered south.
Saylorville Reservoir creates the dominant northwestern lowland
Saylorville Reservoir is the most prominent water feature on the terrain-and-water map. It forms a long north-south reservoir valley in the northwest, with Big Creek Lake shown separately near its northern side. The reservoir corridor is also one of the most obvious low areas on the elevation map.
Beaver Creek runs south on the western side of the reservoir and continues toward the metropolitan area. Smaller tributaries enter the reservoir and nearby valleys from the surrounding uplands. The contrast between these low corridors and the higher northern interior is especially clear when the water and elevation sheets are viewed together.
The terrain-and-water sheet is intended for geographic reference rather than flood forecasting, navigation, current water levels, parcel boundaries, or legal water limits. Its main value is showing how reservoirs, rivers, and creeks fit around the urban area and surrounding uplands.
Raccoon River and eastern streams divide the southern and eastern hills
Raccoon River enters from the southwest and bends through the lower terrain near the Des Moines urban area. Grays Lake and Lake Easter provide smaller water references within the southern metropolitan zone. On the elevation map, this broad southern corridor appears lower than much of the northern interior.
Skunk River provides a major northeastern reference, while Fourmile Creek runs through the north-central and central-eastern interior. Mud Creek, Spring Creek, and Camp Creek create additional narrow valleys farther east and southeast. These waterways break the higher eastern terrain into a series of ridges and lower channels.
North River is labeled near the southern edge and helps relate the county’s southern drainage to the adjoining Warren County area. Looking at Saylorville Reservoir in the northwest, Raccoon River in the southwest, and Skunk River in the northeast shows that Polk County’s low terrain is spread among several different drainage systems.
Elevation ranges from 229 to 319 meters
The supplied elevation map shows an actual county range of about 229 to 319 meters, with a mean elevation of 276 meters. Low green terrain follows Saylorville Reservoir, the southern river corridors, and the Skunk River side. Higher brown terrain covers broad sections of the north-central interior and parts of the eastern ridges.
The reservoir corridor cuts deeply into the northern uplands, and its lower terrain continues south toward the metropolitan area. Fourmile Creek and smaller eastern streams form additional green channels through higher ground, while Raccoon River produces another broad lower corridor in the southwest and south.
The difference between the mapped high and low ends is about 90 meters. The colors are designed for broad terrain comparison rather than survey-grade measurement. Exact parcel elevation, road grade, engineering design, or construction work requires original elevation data or professional surveying.
Moving from Des Moines toward the reservoir and eastern rivers reveals the terrain changes
Traveling north from Des Moines toward Ankeny moves out of the broad southern lowland and closer to higher north-central terrain. Turning northwest toward Johnston and Polk City brings the Saylorville Reservoir valley into view, where the elevation drops again along the reservoir and connected stream corridors.
East of Des Moines, Altoona and Bondurant provide useful references for Fourmile Creek and the eastern drainage network. West Des Moines and Urbandale are closer to the Raccoon River and western lowland system. Matching those city names with the waterways makes it easier to move between the road, water, and elevation maps without losing orientation.
Choose the Polk County map that fits the task
Use the general county map when you need major cities and roads in one view. It is the quickest way to compare Des Moines, Ankeny, Johnston, West Des Moines, Altoona, and Bondurant with I-35, I-80, U.S. 69, Iowa 163, Iowa 330, and Iowa 415. The city map is better when the goal is to compare the six highlighted communities and their mapped population ranking.
The terrain-and-water map is best for Saylorville Reservoir, Big Creek Lake, Beaver Creek, Fourmile Creek, Raccoon River, Skunk River, Grays Lake, Lake Easter, and the smaller eastern streams. The elevation map adds the 229–319 m range and makes the major river lowlands and higher northern and eastern uplands much easier to compare.
The WebP images in the article are optimized for quick browser viewing. For printing, classroom use, presentations, or closer comparison, the ZIP below contains the county, major-city, terrain-and-water, and elevation maps as high-resolution JPG files. They are general-reference graphics and do not replace legal boundary records, current transportation data, flood information, or precise survey measurements.
Frequently Asked Questions
Which map is best for comparing Des Moines and Ankeny?
The general county map is the best starting point. Des Moines occupies the southern-central part of the county, Ankeny lies to the north, and I-35 provides the clearest road reference between them. I-80, U.S. 69, and Iowa 415 add context around the two urban areas.
Where can I see Saylorville Reservoir and the main rivers?
The terrain-and-water map shows Saylorville Reservoir, Big Creek Lake, Beaver Creek, Fourmile Creek, Raccoon River, and Skunk River. Grays Lake and Lake Easter are also labeled within the southern metropolitan area.
What does the 229–319 m elevation range show?
Lower terrain follows Saylorville Reservoir and several southern and eastern river corridors, while higher ground occupies much of the north-central interior and parts of the eastern ridges. The mapped mean elevation is 276 meters. Precise site elevations require original elevation data or professional survey information.
Map File Information
The ZIP contains four high-resolution JPG maps for Polk County, Iowa: county, major cities, terrain and water, and elevation.
- Included Files: Use only the versions confirmed in the article and supplied images
- File Type: Use the confirmed download contents
- Intended Use: Printing, education, presentations, and map-based projects
Related Maps
Sources and reference data
Polk County’s official Public Works map page provides county-specific map resources, while the federal links below provide boundary, hydrography, and elevation source data.
- Polk County Iowa Public Works – Maps
- U.S. Census Bureau TIGER/Line Shapefiles
- USGS National Hydrography
- USGS 3D Elevation Program
These maps are intended for general geographic reference, learning, printing, and visual comparison. Legal boundaries, ownership, current road conditions, flood risk, water levels, and precise elevations should be checked against the responsible agency’s current records.
Green Map creates custom-edited map images using open geographic data sources such as geoBoundaries, Natural Earth, OpenStreetMap, and government open data.
These maps are edited visual materials, not raw data files, and are provided for education, documents, presentations, and graphic reference.
