USFS · Illinois

Midewin National Tallgrass Prairie

The Midewin National Tallgrass Prairie (MNTP) is a tallgrass prairie reserve and is preserved as United States National Grassland operated by the United States Forest Service. The first national tallgrass prairie ever designated in the United States and the largest conservation site in the Chicago Wilderness region, it is located on the site of the former Joliet Army Ammunition Plant between the towns of Elwood, Manhattan and Wilmington in northeastern Illinois. Since 2015, it has hosted a conservation herd of American bison to study their interaction with prairie restoration and conservation.

From Wikipedia, licensed CC BY-SA 4.0.

National Forest27,566 acresUSFSIL6 Forest Service sites10 trails
Official page at U.S. Forest Service ↗

Facts

Where each comes from ↓
DesignationNational Forest
Managed byU.S. Forest Service
StateIllinois
Size27,566 acres
Forest Service code0915, region 09
Center point41.38° N, 88.11° W
Night skyNoticeable light pollution (Black Marble reading 102)

Boundary map

2 outlines

Boundary, simplified to about 0.005 degrees Forest Service recreation site

The outline is the agency boundary simplified for display, so small parcels and inholdings may not show. The agency page has the authoritative map.

Weather by month

NOAA climate normals →
Weather by month near Midewin National Tallgrass Prairie20°30°40°50°60°70°80°January: 1.99 inches of precipitation, 5.0 inches of snowFebruary: 1.78 inches of precipitation, 6.2 inches of snowMarch: 2.27 inches of precipitation, 2.1 inches of snowApril: 3.93 inches of precipitation, 0.1 inches of snowMay: 4.53 inches of precipitation, 0.0 inches of snowJune: 4.30 inches of precipitation, 0.0 inches of snowJuly: 4.55 inches of precipitation, 0.0 inches of snowAugust: 3.97 inches of precipitation, 0.0 inches of snowSeptember: 3.17 inches of precipitation, 0.0 inches of snowOctober: 3.14 inches of precipitation, 0.0 inches of snowNovember: 2.46 inches of precipitation, 0.3 inches of snowDecember: 1.94 inches of precipitation, 3.2 inches of snowJanFebMarAprMayJunJulAugSepOctNovDecJanuary: 23.9°F averageFebruary: 27.6°F averageMarch: 38.1°F averageApril: 49.4°F averageMay: 60.2°F averageJune: 70.1°F averageJuly: 73.9°F averageAugust: 72.3°F averageSeptember: 65.7°F averageOctober: 53.3°F averageNovember: 40.4°F averageDecember: 29.4°F average0 in2 in4 in6 in8 inTemp °FInches
The line is the average temperature and the bars are average precipitation at Joliet Brandon Rd Dam, 9 miles from the center point at 543 feet, station USC00114530 in the NOAA monthly climate normals for 1991 to 2020. Precipitation totals about 38 inches a year. The dotted line is average snowfall, about 17 inches a year on the same inches scale.

Large units span more than one climate. The station stands in for the center point, and the outer parts of the boundary can be warmer or colder.

Trailheads and sites

Forest Service directory · 6

The Forest Service lists 6 recreation sites in this forest, among them 2 viewing Plantss, 2 viewing Wildlifes, 1 visitor center, 1 viewpoint. Each links to its page on fs.usda.gov, which carries the season, fees and current status.

Distance is from the center point of the boundary, not from a road or town.

Trails

Every trail on Trailhead Atlas →

The Forest Service trail layer records 10 named trails in this forest, 29 miles in all.

TrailMiles
Twin Oaks Trail ↗5.8
Henslow Trail ↗5.2
Blodgett Marsh Trail ↗4.6
Group 63 Trail3.4
Route 53 Trail2.6
Bailey Bridge Trail2.4
Hedgeapple Trail1.5
Prairie Creek Woods Trail1.5
Group 63 Trail Spur1.2
Turtle Pond Trail0.3

Lengths and allowed uses come from the Forest Service trail layer by way of Trailhead Atlas. This trail list was copied from Trailhead Atlas on November 1, 2026 and is copied again on each weekly run. Trails in plain text have no page there yet.

All 10 trails in Midewin National Tallgrass Prairie on Trailhead Atlas ↗

Explore

Nearby on the other atlases

National Park System units within 30 miles · Park Atlas
National Historical Park · 29 mi
Pullman National Historical Park
National Register listings within 15 miles · 23 in all · Register Atlas

Landmarks are listed first, then by distance from the boundary.

Guidebooks for Illinois

We earn a small commission if you buy through these links. It does not change what we list.

Titles come from Open Library's catalog, matched by subject heading or by title.

Reference

Questions people ask

How big is Midewin National Tallgrass Prairie?

27,566 acres.

Source: Forest Service boundary data

Who manages Midewin National Tallgrass Prairie?

The U.S. Forest Service.

Source: U.S. Forest Service

What state is Midewin National Tallgrass Prairie in?

Illinois.

Source: How states are assigned

How do I get to Midewin National Tallgrass Prairie?

A point inside the boundary is at 41.376° N, 88.112° W. Pullman National Historical Park is 29 miles away. The official page carries directions and the office address.

Source: U.S. Forest Service

Which national parks are near Midewin National Tallgrass Prairie?

Pullman National Historical Park (29 mi). Park Atlas has fees, hours and alerts for each.

Source: Nearby on the other atlases

Are there historic places near Midewin National Tallgrass Prairie?

The National Register has 23 listings within 15 miles, including Small--Towle House and Eagle Hotel.

Source: Register Atlas

Sources

  • Boundary, name, acreage and code: the Forest Service Enterprise Data Warehouse.
  • States and territories: computed by intersecting the boundary with Census state polygons and coarse outlines of the territories and outlying islands. A place is listed when it holds at least one percent of the area. A boundary that touches no outline is listed under the nearest one.
  • Description: Midewin National Tallgrass Prairie on Wikipedia, CC BY-SA 4.0. The article was accepted because its title contains this unit’s name.
  • Campgrounds: the Campsite Atlas index of federal campgrounds, matched to this boundary at build time.
  • Trailheads and sites: the Forest Service Recreation Opportunities layer, matched by forest code.
  • Trails: the Trailhead Atlas open-data file of Forest Service trails, matched by forest code.
  • Night sky: NASA Black Marble (VIIRS, 2016 composite) sampled at zoom 6 around the center point.
  • Weather, alerts, air quality, river flow and earthquakes load live in your browser from NWS, AirNow, USGS and iNaturalist when you open the page.