The Jacksville Esker, also known as West Liberty Esker, Miller Esker, and the West Liberty Hogback is the best preserved esker in Pennsylvania. “An esker forms when meltwater drains into a glacier through fractures and flows through ice tunnels at the base of the glacier. Sand and gravel deposited along the tunnel floor remain as an elongate, often sinuous, ridge standing above ground level when the ice melts.” DCNR Page
Although parts of the six mile long Jacksville Esker have disappeared through erosion and mining, this beautiful, 23,000 year old, winding ridge of sand and gravel is a gentle reminder of a time gone by. It is a reminder that a glacier was here. It is also a testament to the insight and generosity of one local resident, Mrs. Violet Miller.
In the 1970’s, in a generous gesture, Mrs. Violet Miller sold the wonderful portion of the esker on her property to the Western Pennsylvania Conservancy, so that the Conservancy could protect the esker for generations to come. Located near West Liberty Road, this part of the esker is open to the public and the ridge is easy to see. As you walk from the bottom to the top of the esker you realize just how large it is. And standing on the top, imagining you are inside the ice tunnel under the glacial ice is an exhilarating experience. To the north of the esker is a large wetland and to the east is Tamarack Lake. Both of these privately owned wetlands are thought to have been glacial features; the lake having once been a kettle bog.
If you look back towards the road, across the farmed fields, and to the wooded hills, you may let out a long sigh at the sight of this lovely, peaceful valley. No wonder so many people come to this area, to visit or to settle down. It is a beautiful reflection of nature’s bounty, and man’s cooperation with it.
Continuing east across Swope Road you come to another beautiful long section of the esker. This is the tail of the esker which ends near the intersection of Moore and West Liberty Road. In a letter to DEP dated November 7, 2007, DCNR refers to this portion of the esker expressing concern over its inclusion in the mining permit application. DCNR explains the geologic importance of the esker as well as the fact that the esker “is one of the geologic heritage sites currently being reviewed for inclusion in the PNHP (Pennsylvania Natural Heritage Program) review database”. The letter also states, ”We request that, if this permit is approved, that care is taken to prevent the destruction of this rare geologic feature.”
Other geologists, teachers, and students have raised concerns since they also find the esker to be a place of significant scientific and educational value.
To the north of this portion of the esker, just outside the mining permit area, is a large high value wetland, known as the West Liberty Bog, another kettle bog. Nestled against the curve of the esker, this magical, isolated wetland provides a home and sustenance to many species of birds, animals, and plants. (There are ducks, herons, eagles, egrets, deer, muskrats, snakes, spring peepers, turtles, salamanders, beavers, coyotes, fox, bear in the area to name a few.) Some species are threatened or endangered. The water from the wetland leaves and flows under Swope Road into Tamarack Lake, then on to Black Run, the Slippery Rock Creek, and eventually to the Ohio River.
In a DCNR publication, “The Geology of Pennsylvania’s Groundwater,” page 16, it states, “Water is not just stored in the ground. It flows around grains and through the cracks within and the spaces between rock layers. What forces cause groundwater to move through rocks and sediments? The main force causing groundwater to flow is the same force that causes surface water to flow – gravity. Groundwater always flows downward from a recharge areas on hills toward discharge areas in valleys. The water that you see in a stream came from a higher elevation, either from surface water upstream or from groundwater that recharged at a higher elevation.” More Info
Considering this fact, some local residents, geologists and hydrologists are concerned that removing the esker could severely affect the water supply that feeds the springs and stream of the West Liberty Bog and Tamarack Lake. And one can only imagine what would happen to the hundreds of creatures who depend on this ecosystem for their food, shelter, water, and breeding grounds if the water dried up or diminished. It seems an awfully big risk to take.
The local Audubon Society is also concerned that without the natural buffer provided by the esker, birds and other wildlife could suffer from the night time lighting on the washing plant, and the dust, noise, and commotion of the mining operation. They are also very concerned that the proposed truck route, (View map) which will cut through this marvelous wooded and wetland area via Swope Road could pose a great threat to the survival of the wildlife. No longer a safe haven, this area would become a thoroughfare of heavy truck traffic with little respite from the sights, sounds, and smells of mining.
So you can see, this wonderful esker provides many valuable functions for humans and non-humans alike. From teaching us about the past, to helping us observe life in the present, the esker is a living monument that spans centuries, and helps us see the delicate and interconnected balance of life.
And perhaps, if we are patient, it will teach us even more.
