The waterfalls on the Yough River at Ohiopyle State Park.
Bob Frye/Everybody Adventures
Waterfalls are the result of science begetting beauty.
Lovely to look at – especially when hiking at this time of year, when colorful leaves dance beneath them and color their edges – they’re typically the result of some form or another of brute force.
Volcanic activity creates waterfalls, said Simeon Suter, geologist supervisor fro Pennsylvania’s bureau of topographic and geologic survey. So, too, do geologic faults.
At their most basic, though, they’re the byproduct of flowing water carrying sediment that erodes soft rock and leaves ledges and cliffs of harder rock behind.
One of the many waterfalls at Ricketts Glen State Park.
Bob Frye/Everybody Adventures
The “ridge and valley province” of Pennsylvania is a prime example. It runs from southcentral Pennsylvania up through the northeast. The landscape formed when rocks were folded and uplifted, Suter said.
Two types of rock, sandstone and shale, predominate, but with one lording over the other.
“The sandstone is going to be more resistant to erosion. The shale is going to give way all the time,” Suter said.
That’s why places like Ricketts Glen State Park – with about two dozen falls between 11 and 94 feet – look the way they do.
It’s unknown how long waterfalls take to form or how long they last, Suter added. The science of geology is relatively young, he added.
Yet what’s clear is that the speed with which falls disappear is a function of two things: the volume of water passing over them and the amount and type of material being swept along. More water with more rough stone means more erosion.
Niagara Falls, for example – while not in danger of disappearing any time soon – is eroding “amazingly fast,” he said.
“Over time, erosion is going to win out. It works 24/7 to just keep going,” Suter said.
No one alive today has to worry about missing out on seeing Niagara, of course.
But neither do hikers or backpackers have to travel that far to take in some spectacular waterfalls. Pennsylvania state parks and forests are home to quite a few – a list of some of the best is available by clicking here — that are worth visiting.
“It’s really impressive, the number of waterfalls we have in Pennsylvania,” Suter said. “When you add everything up, there are quite a few.
How impressive each is depends on time of year and water flows.
Cucumber Falls in Ohiopyle State Park, for example, can range from a relative trickle to a raging, roaring beast of a falls depending on how much water is moving. Adams Falls in Linn Run State Park is always smaller, but can likewise vary on its own scale, too.
All, though, are picturesque in their own ways.
And now is one of the best times to go see them.
