Irwin Prairie State Nature Preserve (Oak Openings Loop)
Irwin Prairie is a low-lying, almost permanently saturated area. Its dominant feature is a massive twig-rush wet prairie that covers much of the 226-acre preserve.
Key Species by Season
Spring
- Virginia Rail
- Sora
- Alder Flycatcher
Summer
- Wilson's Snipe
- American Woodcock
- Black-Billed Cuckoo
Fall
- Philadelphia Vireo
- Connecticut Warbler
- Yellow-Bellied Flycatcher
Winter
- Northern Shrike
- Hairy Woodpecker
- Black-Capped Chickadee
At-a-Glance
84 - Irwin Prairie State Nature Preserve
Ohio Department of Natural Resources Division of Natural Areas and Preserves
9987 W. Bancroft
Holland, OH 43528
419.445.1775
Public Access
Open daily from sunrise to sunset
Amenities
Hiking Trails, Handicap Accessible Trails
Driving Directions
From I-475/U.S. Route 23, follow U.S. Route 20 west approximately 3 miles to Centennial Road; south about 1 mile to Bancroft Street; and then west on Bancroft Street to the preserve entrance. Parking lot and trail system present.
What to Look For
In the Oak Openings, shifts in elevation of just a few feet mean radical changes in plant communities. Dry sandy ridges support black oak and other upland species, while low-lying areas are often permanently saturated. Irwin Prairie is of the latter type, and its dominant feature is a massive twig-rush wet prairie that covers much of the 226-acre preserve. A boardwalk that is over a mile in length offers easy access to the wetlands. Spring—April and May—is the most productive season, but be aware that the incredibly loud din raised by legions of spring peepers and western chorus frogs can down out the birds near dusk. An early evening stroll should produce displaying American Woodcock and Wilson's Snipe—this is one of few breeding sites in Ohio for the latter. Listen for both bitterns, and Virginia Rail and Sora. Some years, both Alder and Willow flycatchers are present, as well as Marsh and Sedge wrens.
Noteworthy Rarities
There are a number of records of Yellow Rail from along the boardwalk. Late April and May is the time to listen for this secretive species. A Black Rail was found here in 1980. Bell's Vireo once bred here and could turn up again, and Canada and Mourning warblers have summered. There are a number of records of Connecticut Warbler from the scruffy woods at the end of the boardwalk; late May is the time to seek this rare migrant.
Natural Features
At least 18 species of state-listed rare plants occur in the preserve. In late fall, fringed gentian (Gentianopsis crinita) can be found along the boardwalk. The endangered grass-leaved arrowhead (Sagittaria graminea) can be seen in bloom in May near the observation tower at the fair end of the boardwalk. An endangered dragonfly, the frosted whiteface, was found in the preserve in 2010.
Local Resources
Destination Toledo
ODNR Division of Natural Areas and Preserves
Ohio Ornithological Society
About the Oak Openings Loop
The Oak Openings is legendary for the diversity of rare plants that occur here. The highly specialized habitats that comprise this ecosystem support more species of state-listed rare plants than any other region of Ohio.
The defining feature of the Oak Openings is sand. This unique region is situated on the former shores of preglacial Lake Warren, modern day Lake Erie’s much larger predecessor. As Lake Warren receded, it left its dunes and beach ridges in its wake, and these sands are now carpeted with oak savannas, dry prairie, and wet sedge meadows in low-lying areas.
What To Look For
The Oak Openings buffers the western end of Lake Erie, and lies just west of Toledo. The sandy prairies, wet sedge meadows, and oak savannas of this highly specialized ecosystem once covered about 300 square miles; today, only about 130 square miles remain. This region contains the best habitats to be found in the northwestern corner of Ohio, and many bird species breed in the Oak Openings that are difficult or impossible to find elsewhere in this region. The Oak Openings is also known for its fall hawk flights. Raptors streaming around the western end of Lake Erie funnel through this area, sometimes in large numbers. The largest kettle of Broad-winged Hawks recorded in Ohio was seen near Perrysburg – about 20,000 birds on September 18th, 2002.
Noteworthy Rarities
A number of species breed in the Oak Openings that are a challenge to find elsewhere in northern Ohio, such as Eastern Whip-poor-will, Summer Tanager, and on occasion, Blue Grosbeak. The premier breeding rarity is the Lark Sparrow; the Oak Openings population is the easternmost in this species’ range. Other western species, such as Clay-colored Sparrow and Western Meadowlark, have bred or attempted to breed in this area as well. Golden Eagles are regularly spotted in migration, and good numbers of winter finches can occur. The last Ohio record of Pine Grosbeak came from the Oak Openings, in winter 2007-08. The total species list for the loop is about 300, and three of those – Atlantic Puffin (only Ohio record), Black-billed Magpie, and Mountain Bluebird – have been found only in this region.
Natural Features
The Oak Openings is legendary for the diversity of rare plants that occur here. The highly specialized habitats that comprise this ecosystem support more species of state-listed rare plants than any other region of Ohio. A great diversity of animals lives in these plant communities. Spotted turtles, blue racers, and blue-spotted salamanders are just a few of the unusual animals that can be found. The poster child for rare Oak Openings animals is the tiny Karner blue butterfly, a federally endangered species. It depends in part on rare wild lupine plants that flourish in the Oak Openings savannas.
9987 W. Bancroft, Holland, OH 43528
