The early industrial economy of the region was based, in large part, on the iron, lime, oil, and coal contained within the sedimentary layers.
The Vanport Limestone originally was named the "ferriferous limestone" for the large amount of iron mineralization in the upper part of the formation. The iron ore was surface-mined in the mid-1800s to feed three furnaces-the Wilroy and Hope, near Rose Point upstream from McConnells Mill State Park, and the Lawrence, in Hell Hollow. When the vast iron-ore resources of the Lake Superior region became available in the 1870s, all of the local ore-mining operations and small furnaces were abandoned.
The ruins of the Wilroy furnace's stone stack can still be seen on private property at “A” on the centerfold map,.
but nothing marks the sites of the other furnaces except for some glassy slag scattered on the surface of the ground.
In addition to exploitation of its upper layers for iron ore, the Vanport Limestone itself was also locally quarried...
and burned to produce agricultural lime..
In the gorge 6 miles south of the old grist mill, an oil seep coated a large rock on the east bank of the main stream (B). After oil was produced from drilled wells at Titusville in 1859, the "Slippery Rock" and other seeps along the gorge naturally excited local drillers. By 1864, at least 17 wells had been drilled along the creek. They were shallow but yielded about 45,000 barrels of oil before groundwater invaded the sandstones and prevented further oil production.
Drilling activity then shifted eastward into the Muddy Creek valley. By the 1890s, the Muddy Creek field was producing oil from formations deeper than those tapped in the Slippery Rock Gorge. The production continued in decreasing quantity into the 1930s. As production diminished, the wells were abandoned but never properly cemented and plugged. All these wells had to be located and sealed to prevent oil seeps into the bottom of modern Lake Arthur, which covers much of the old Muddy Creek oil field.
Most of the mineable coal is above the Vanport Limestone in the Kittanning Formation (see cross section). It crops out away from the rim of the gorge and around the sides of the Muddy Creek valley. Much of this coal was mined, both by underground and strip mining, before the stringent laws regulating mine reclamation were passed in the 1960s and '70s. Consequently, before modern Lake Arthur was flooded, extensive reclamation was needed to prevent lake and land pollution from mine drainage.