A Prairie place
Jennings Environmental Education Center preserves 20-acre swath of prairie surviving since Ice Age
Ben Moyer
How far do you think you’d need to drive to see a prairie? To Iowa? Minnesota? Somewhere on the far side of Ohio? Do prairies even still exist?
The answers might surprise. Prairies do still exist, but only as a tiny fraction of their original extent. And you can see one as near as Slippery Rock, Pa, a mere two-hour drive north.
There, the Jennings Environmental Education Center preserves a 20-acre remnant prairie where it originated in the wake of melting glaciers. It’s the only preserved prairie in Pennsylvania, and possibly the easternmost surviving prairie in North America.
Jennings Environmental Education Center is part of Pennsylvania’s state park system, the same assembly of significant public lands that include Ohiopyle State Park and, hopefully soon, Laurel Caverns. State park staff use the prairie ecosystem at Jennings as an educational resource in school programs, university courses, and workshops for teachers.
Don’t imagine a flat expanse of neat grass at Jennings. Instead, it’s a gently sloping mix of grasses and wildflowers, many growing to about waist-height of the average visitor.
Most prairie flowers bloom in mid-summer and the prairie is approaching peak bloom now. The most celebrated of Jennings’ dozens of open-country wildflowers is the blazing star, which grows as a four-foot-high spike, packed with rose-purple flowers nearing the top. Blazing star’s purple mixes beautifully now with yellow goldenrods, black-eyed Susans, coneflowers and oxeye. Other flowers spice the scene with white, orange, blue, and scarlet. Hundreds of butterflies hover among the multi-colored blooms.
“Prairie” is a French word that we use today because the English language had no word to describe sunny openings in the vast expanse of forest the English were accustomed to along the eastern seaboard. Generally, prairie ecosystems occur farther west than Pennsylvania because the drier climate there limits tree growth. The Jennings prairie and others that were scattered on the Allegheny Mountains’ western flank began as lakebeds during the Ice Age. As the glaciers melted 10,000 years ago, water collected in low places as lakes. When the lakes dried up thousands of years later, the clay that had settled on the bottom formed soil too poor to support trees but grasses and flowers could flourish, so patches of prairie persisted within the woods.
Jennings prairie is home to another acclaimed resident that inhabits only four known locations in Pennsylvania. It’s the massasauga rattlesnake, smaller and even more secretive than our more common timber rattlesnake of the mountains. The massasauga requires open meadow-like habitats where it hunts mice and small amphibians. Massasauga rattlesnakes hibernate over winter in underground burrows excavated by the brown mudbug crayfish.
The massasauga rattlesnake is officially listed as an Endangered Species in Pennsylvania, so harming them is forbidden. This snake seldom exceeds two feet in length. Its small size and shy manner present little danger to visitors, but the species is venomous and should be respected. Trails at Jennings are wide and well-mowed, so there’s little chance of accidentally stepping too close to a massasauga rattler.
Farther west where prairies were extensive, few prairie ecosystems remain because the open flat land was claimed for agriculture. Western prairies had a different origin than the Jennings relict so have richer soils, well-suited to farming.
Surrounding woodlands try to encroach on the Jennings prairie but the park maintains the open setting by frequent burning during winter. Fire was part of the original prairie ecosystem, which discourages woody growth.
Prescribed fires are burned in winter, during periods without snow, because the vegetation burns well then and because endangered massasauga rattlesnakes are safely underground.
Five miles of hiking trails network the Jennings prairie. Most are easy walking due to the gentle terrain. A visitor center features exhibits that explain the prairie’s origins and the challenges of maintaining a prairie in a forested region.
Jennings exists as a protected place today because botanist Otto Jennings noticed blazing star blooming there in 1905. Jennings knew blazing star was an indicator of prairie, and he campaigned for the site’s preservation. The Western Pennsylvania Conservancy purchased the site in 1951 and later conferred the tract to the state of Pennsylvania.
Jennings Environmental Education Center is reached from Rte. 528 in northern Butler County about four miles northeast of Slippery Rock Borough. Trails are open sunrise to sunset every day, and the office, visitor center, and nature shop are open 8 a.m. to 4 p.m. Monday through Friday. For information on educational opportunities at Jennings, call 724-794-6011 or visit www.dcnr.pa.gov/StateParks.
Ben Moyer is a member of the Pennsylvania Outdoor Writers Association and the Outdoor Writers Association of America.