Elevation Map of Illinois

This Illinois topographic elevation map shows the Prairie State in 24 terraced elevation bands. The scale runs from 85 meters (279 ft) up to 376 meters (1,234 ft). Each band steps through the relief in sequence, so the map reads like a physical relief model. Lowlands appear in deep greens, middle elevations warm into golds and reds, and the highest terrain fades into grays and whites.

Illinois covers about 149,995 square kilometers (57,913 sq mi). Glaciers flattened most of Illinois, but the unglaciated Driftless corner in the northwest and the Shawnee Hills in the south still rise on this topographic map.

Highest Point in Illinois

Charles Mound, at 1,234 ft (376 m), is the highest point in Illinois. On this topographic map, it anchors the pale summit end of the elevation scale.

Lowest Point in Illinois

The lowest point in Illinois is the Mississippi River at Cairo, at an elevation of 279 ft (85 m). On the relief map, this terrain fills the deep green base of the color scale.

Illinois Map Datasets

I prepared this relief map with elevation data from the AWS Terrain Tiles dataset. The dataset builds on the NASA Shuttle Radar Topography Mission (SRTM) along with other open topographic sources, and it serves global elevation data as map tiles that anyone can access.

The map spaces its 24 elevation bands with a blend of two methods. Half of the spacing follows equal elevation steps. The other half follows equal land area, a technique known as histogram equalization.

Why blend them?

A fixed interval scale would leave flatter regions sitting in a single color, which hides their topography. On the other hand, full histogram equalization would push a quarter of the land into summit tones. The blend lets this elevation map use the entire relief palette while the legend stays honest. Each label marks the true elevation behind its band, which is why the values are not evenly spaced.