Williamson County, IL Elevation & Topographic Map

Topographic elevation map of Williamson County, Illinois, shaded from 350 ft on the northwest side to 720 ft on the southwest side
Elevation
720 ft 220 m630 ft 190 m580 ft 175 m490 ft 150 m400 ft 120 m350 ft 105 m
Contours every 500 ft, bold every 2,500 ft
USGS 3DEP · U.S. Census Bureau
⤓ Download this map
How to use this mapviews, tools and data
Elevation
Ground colored by height from green (lowest) to white (highest), with contour lines every 40–500 ft (USGS data).
Satellite
A 2016 satellite photo at 33 ft (10 m) detail; contours off.
3D
Tilt and turn the terrain; hills are raised 1.5×, or set ×1 for true height.
Click or tap anywhere
The exact elevation of that spot in ft and m.
Measure
Pick two points for the climb, descent and grade along a straight line.
County area
Fades everything outside the official county boundary (US Census).

Elevation Data

Williamson County averages about 470 ft (140 m) above sea level across all its land. Its ground runs from 350 ft on the northwest side to 720 ft on the southwest side.

Average elevation
470 ft 140 m
all land inside the county
Highest
720 ft 220 m
on the southwest side
Lowest
350 ft 105 m
on the northwest side

Williamson County spans about 370 ft of height, so no single spot tells the whole story. The ruler shows where most of its land lies, and where the other numbers you'll see come from.

FigureElevation
Average of all land470 ft140 m
Highest point
Inside the county, on the southwest side
720 ft220 m
Lowest point
Inside the county, on the northwest side
350 ft105 m

Elevation profile, south to north

18 mi south to north through Marion.

Topographic Map

Topographic elevation map of Williamson County, Illinois, shaded from 350 ft on the northwest side to 720 ft on the southwest side
County boundary (dashed) over shaded terrain, with contours every 40 ft (12 m).
Location
County in Illinois, United States
Population
67,064 2024 est.
Land area
420.2 sq mi + 24.1 sq mi water
Density
160 per sq mi
Time zone
Central UTC−6 / −5
Landform region
Central Lowland 95%
Drains to
Gulf of America
⤓ Download this map

WebP, 1200 × 900. Free to use: credit “ElevationOf.com” with a link to this page.

Sources: U.S. Census Bureau, USGS

Nearby Places

Neighboring counties sharing a border, by average

  1. Union County500 ft
  2. Johnson County500 ft
  3. Williamson County470 ft
  4. Jackson County460 ft
  5. Franklin County440 ft
  6. Saline County420 ft

Rankings by average elevation

Peaks and hills highest inside

  • McKinney Hill520 ft
All 18 towns in Williamson County by typical elevation
  1. Creal Springs520 ft
  2. Crab Orchard510 ft
  3. Spillertown500 ft
  4. Pittsburg480 ft
  5. Energy460 ft
  6. Crainville460 ft
  7. Carterville440 ft
  8. Whiteash440 ft
  9. Marion440 ft
  10. Johnston City430 ft
  11. Cambria430 ft
  12. Stonefort420 ft
  13. Herrin420 ft
  14. Bush410 ft
  15. Blairsville400 ft
  16. Colp390 ft
  17. Hurst390 ft
  18. Freeman Spur390 ft
How we measure
  • Average: every USGS 3DEP bare-earth cell of land inside the Census county boundary (TIGER/Line, Jan 1 2026), weighted equally, on a 1 arc-second (≈100 ft, 30 m) grid. Land means the boundary minus Census area water.
  • Highest and lowest: the highest land cell. Lowest: the lowest land cell; coastal ground within 3 ft (1 m) of named tidal water counts as sea level.
  • Nearby Places: neighboring counties and rankings use each one's average elevation, on its own grid, the same figure its page shows. Peaks and hills: the highest summits inside the county with at least 980 ft (300 m) of prominence, then the highest federal (GNIS) summits inside it when there are fewer than 5; each is the 3DEP top on a ~7 ft (2 m) window, or the NGS published height when a usable survey mark sits within 160 ft (50 m) of it (shown as published).
  • Towns: each town's typical elevation (population-weighted median of its own 2020 blocks at 1 arc-second); a town is listed when any of its 2020 residents live in the county.
  • Rounding: computed heights are rounded to 10 ft (5 m), or to 1 ft (1 m) under 100 ft; 3DEP is good to about a meter, not a foot. Published figures (NGS survey heights) are shown as their publisher gives them.
  • Datum: North American Vertical Datum of 1988 (NAVD 88). NGS plans to replace NAVD 88 with a new datum (NAPGD2022); heights will then shift slightly.
  • Sources: USGS 3DEP, GNIS, Watershed Boundary Dataset and physiographic provinces; U.S. Census Bureau (TIGER boundaries and water, 2020 blocks, 2024 population estimates, county adjacency); NOAA NGS survey heights; BTS time zones. All public domain.