This story first appeared in PA Local, a weekly newsletter from Spotlight PA that takes a fresh, positive look at the incredible people, beautiful places and delicious food of Pennsylvania. Register for free here.

Deep in the green southwest of Pennsylvania, on the bend of a river flowing from south to north, lies one of the wettest places in the state.

Named for its waterfalls, Ohiopyle State Park in Fayette County receives exceptionally high rainfall each year. It is lush and supports great biodiversity. But is it a rainforest?

There are several temperate (not tropical) rainforests in the Appalachians, and at least one website lists Ohiopyle State Park as the northernmost example.

The park appears to meet several criteria established in 1991 by forest ecologist Paul Alaback, the Internet's most popular standard-setter for temperate rainforests.

Fires are rare, temperatures are relatively mild and plants remain dormant in winter.

But it misses a critical benchmark – just barely.

“Alaback's definition is annual precipitation greater than 1,400 mm,” said Ben Lee, a former postdoctoral fellow in biology at the Carnegie Museum of Natural History. “Although not an authoritative source, this reference gives the annual precipitation at Ohiopyle as 54.21 inches, or ~1,370 mm per year, just under the threshold,” Lee explained in an email. “As far as I know, there is no place in Pennsylvania that would be considered a temperate rain forest.”

A review of data from the National Weather Service weather station closest to the park also shows that rainfall in the park does not reach the minimum.

So the closest area to meet Alaback's requirements would be the Monongahela National Forest in West Virginia – an hour and fifteen minutes south. And there are even bigger qualifiers in the Smoky Mountains in Tennessee and in North Carolina.

But this is where things get murky. Whether the Appalachian rainforests are actually considered rainforests depends largely on who you ask.

“Outside the Pacific Northwest, temperate rain forests were and are loosely defined and overlie eastern deciduous forests,” said Eric Burkhart, program director for Appalachian botany at the Shaver's Creek Environmental Center in Huntingdon County.

Burkhart, who also serves as a professor in Penn State's College of Agricultural Sciences, added: “There is a Wikipedia page that appears to present an authoritative statement as if it were an accepted fact, but note that the information page is controversial and the references are selective and do not include many of the authoritative references for the classification of North American vegetation. The most scientific and up-to-date treatment of North American forest types is this [U.S. Forest Service atlas]and note that there are no designated temperate rainforests outside the Pacific Northwest.”

The US Forest Service confirmed in an email to PA Local: “Forest type classification varies by organization, so the short answer is no. The Forest Service does not classify the forest types in the Appalachian Mountains as temperate rainforests.”

It is worth noting that, as Lee pointed out, a slightly broader definition than Alaback's original followed the 2011 publication. Temperate and boreal rainforests of the worldto which Alaback contributed.

Although Ohiopyle does not meet these requirements, it is undoubtedly special and ecologically significant.

“We're on the leeward side of the mountain and we're taking in all the moisture that's coming across the plains, and that's the first resistance it encounters – this part of Chestnut Ridge gets a lot of precipitation,” said Amos Ludwig, an environmental educator with the park.

“The Youghiogheny River Gorge provides a sort of microclimate and, as far as Pennsylvania is concerned, there are many species that are only found here in the park. These species come from the south and this is their only habitat in the entire state,” he added. The endangered St. Barbara's Button, for example, thrives there.

Of course, climate change is already altering forests, ecosystems and weather patterns, meaning that one day rainforest stands could be turned upside down too.

As someone who grew up in the 1990s, an era of Captain Planet and “Save the Amazon” benefit concerts, this part sounds familiar. And despite all the commercial trappings of this cultural moment, according to Vox, the 1990s saw concrete progress in conservation in places like Costa Rica – home to the “lungs of the world.”

Thirty years later, fear is growing elsewhere.

Barbara Wallace, another environmental educator at Ohiopyle, told PA Local that there is evidence of more flooding, less snowfall, “an insane number of storms” and, last year, a rare tornado.

In view of climate change, Wallace says the park is practicing “large-scale resource management” with its forests, favoring tree species such as oaks that are more resilient to fire and other extremes.

Ephraim Zimmerman, science director of the Western Pennsylvania Conservancy's Pennsylvania Natural Heritage Program, said Ohiopyle's weather will continue to worsen and change, meaning the biggest similarity between the rainforest and the rainforests that fascinated me when I was young is an existential threat and an opportunity to do something about it.

BEFORE YOU GO… If you learned something from this article, please pass it on and donate to Spotlight PA at spotlightpa.org/donateSpotlight PA is sponsored by Foundations and readers like you who are committed to responsible journalism that achieves results.

Spotlight PA is an independent, nonpartisan newsroom operated by the Philadelphia Inquirer in partnership with PennLive/The Patriot-News, TribLIVE/Pittsburgh Tribune-Review and WITF Public Media.