Ricketts Glen State Park covers two different physiographic provinces: the Allegheny Plateau in the north, and the Ridge-and-Valley Appalachians in the south.
The boundary between these is a steep escarpment known as the Allegheny Front, which rises up to 1,200 feet (370 m) above the land to the south.
Within the park, Kitchen Creek has its headwaters on the dissected plateau, then drops approximately 1,000 feet (300 m) down the Allegheny Front in  2.25 miles (3.62 km).
Much of this drop occurs in Glen Leigh and Ganoga Glen, two narrow valleys carved by branches of Kitchen Creek, which come together at Waters Meet.
Ricketts Glen lies south of and downstream from Waters Meet, and here the terrain becomes less steep.
There are 24 named waterfalls in the three glens.

The rocks exposed in the park were formed in the Devonian and Carboniferous periods between 370 and 340 million years ago, when the land was part of the coastline of a shallow sea that covered a great portion of what is now North America.
The high mountains to the east of the sea gradually eroded, causing a build-up of sediment made up primarily of clay, sand and gravel.

Tremendous pressure caused the formation of the sedimentary rocks that are found in the park and in the Kitchen Creek drainage basin: sandstone, shale, siltstone, and conglomerates.

There are four distinct rock formations within Ricketts Glen State Park.
The most recent and highest of these is the late Mississippian Mauch Chunk Formation, composed of "grayish-red shale, siltstone, sandstone, and some conglomerate".
This forms the highest points on the Allegheny Plateau and is found north of Lake Jean, forming the land beneath the Red Rocks Job Corps Center and Cherry Ridge to the east.
The next formation below this is the Mississippian Pocono Formation, which is buff or gray sandstone with  conglomerate and siltstone inclusions.
This forms most of the Allegheny Plateau and underlies the park office, Lake Jean and the former Lakes Rose and Leigh.
The boulders of the Midway Crevasse, which the Highland Trail passes through, are Pocono Formation sandstone.

The third of the rock formations within the park is the Huntley Mountain Formation, from the late Devonian and early Mississippian.
This is made of layers of olive green to gray sandstone and gray to red shale.
The Huntley Mountain Formation is relatively hard and erosion resistant.
It caps the Allegheny Front and has kept it from eroding as much as the softer Catskill Formation, to the south.
The Catskill Formation is the lowest and oldest layer in the park, and is composed of red shale and siltstone up to 370 million years old.
The Allegheny Front within the park is named North Mountain and Red Rock Mountain, with the latter name coming from an exposed band of Huntley Formation red shale and sandstone visible along Pennsylvania Route 487 (PA 487).

Geologists and the official Ricketts Glen State Park web page classify the falls at Ricketts Glen State Park into two types.
Wedding-cake falls descend in a series of small steps.
Within the park, this type of falls usually flows over thin layers of Huntley Mountain Formation sandstone.
In bridal-veil falls, the second type, water falls over a ledge and drops vertically into a plunge pool in the stream bed below.
Within the park, this type of falls flows over Catskill Formation rocks or the red shale and sandstone of the Huntley Formation.
In the park, the harder caprock which forms the ledge from which the bridal-veil falls drops is gray sandstone.
The softer red shale below is eroded away by water, sand and gravel to form the plunge pool.
Brown's book Pennsylvania waterfalls: a guide for hikers and photographers uses four types to classify waterfalls: falls, cascade, slide, and chute.

About 300 to 250 million years ago, the Allegheny Plateau, Allegheny Front, and Appalachian Mountains all formed in the Alleghenian orogeny.
This happened long after the sedimentary rocks in the park were deposited, when the part of Gondwana that became Africa collided with what became North America, forming Pangaea.
Ricketts Glen State Park covers two different physiographic provinces: the Allegheny Plateau in the north, and the Ridge-and-Valley Appalachians in the south. The boundary between these is a steep escarpment known as the Allegheny Front, which rises up to 1,200 feet (370 m) above the land to the south. Within the park, Kitchen Creek has its headwaters on the dissected plateau, then drops approximately 1,000 feet (300 m) down the Allegheny Front in  2.25 miles (3.62 km). Much of this drop occurs in Glen Leigh and Ganoga Glen, two narrow valleys carved by branches of Kitchen Creek, which come together at Waters Meet. Ricketts Glen lies south of and downstream from Waters Meet, and here the terrain becomes less steep. There are 24 named waterfalls in the three glens.
The rocks exposed in the park were formed in the Devonian and Carboniferous periods between 370 and 340 million years ago, when the land was part of the coastline of a shallow sea that covered a great portion of what is now North America. The high mountains to the east of the sea gradually eroded, causing a build-up of sediment made up primarily of clay, sand and gravel.
Tremendous pressure caused the formation of the sedimentary rocks that are found in the park and in the Kitchen Creek drainage basin: sandstone, shale, siltstone, and conglomerates.
There are four distinct rock formations within Ricketts Glen State Park. The most recent and highest of these is the late Mississippian Mauch Chunk Formation, composed of "grayish-red shale, siltstone, sandstone, and some conglomerate". This forms the highest points on the Allegheny Plateau and is found north of Lake Jean, forming the land beneath the Red Rocks Job Corps Center and Cherry Ridge to the east. The next formation below this is the Mississippian Pocono Formation, which is buff or gray sandstone with  conglomerate and siltstone inclusions. This forms most of the Allegheny Plateau and underlies the park office, Lake Jean and the former Lakes Rose and Leigh. The boulders of the Midway Crevasse, which the Highland Trail passes through, are Pocono Formation sandstone.
The third of the rock formations within the park is the Huntley Mountain Formation, from the late Devonian and early Mississippian. This is made of layers of olive green to gray sandstone and gray to red shale. The Huntley Mountain Formation is relatively hard and erosion resistant. It caps the Allegheny Front and has kept it from eroding as much as the softer Catskill Formation, to the south. The Catskill Formation is the lowest and oldest layer in the park, and is composed of red shale and siltstone up to 370 million years old. The Allegheny Front within the park is named North Mountain and Red Rock Mountain, with the latter name coming from an exposed band of Huntley Formation red shale and sandstone visible along Pennsylvania Route 487 (PA 487).
Geologists and the official Ricketts Glen State Park web page classify the falls at Ricketts Glen State Park into two types. Wedding-cake falls descend in a series of small steps. Within the park, this type of falls usually flows over thin layers of Huntley Mountain Formation sandstone. In bridal-veil falls, the second type, water falls over a ledge and drops vertically into a plunge pool in the stream bed below. Within the park, this type of falls flows over Catskill Formation rocks or the red shale and sandstone of the Huntley Formation. In the park, the harder caprock which forms the ledge from which the bridal-veil falls drops is gray sandstone. The softer red shale below is eroded away by water, sand and gravel to form the plunge pool. Brown's book Pennsylvania waterfalls: a guide for hikers and photographers uses four types to classify waterfalls: falls, cascade, slide, and chute.
About 300 to 250 million years ago, the Allegheny Plateau, Allegheny Front, and Appalachian Mountains all formed in the Alleghenian orogeny. This happened long after the sedimentary rocks in the park were deposited, when the part of Gondwana that became Africa collided with what became North America, forming Pangaea. 
Ricketts Glen State Park