Sandstone Nation: Bilger’s Rocks
Sep 06, 2017 12:14PM ● Published by Melanie Heisinger
Ken Boris stands beside the creamy sandstone that went into the U.S. Capitol Visitor Center
Gallery: Sandstone Nation [10 Images] Click any image to expand.
Sandstone NationStory and photographs by Bill Rozday
Bilger’s Rocks are up there in that nondescript high country, where the geographic preference splits between Allegheny and Susquehanna. Drive south on Route 219 from Du Bois to Grampion, turn left at a classic hardware store spilling out onto an intersection, turn left again at a humble railroad overpass. Bilger’s Rocks are a complex of huge Homewood Sandstone cliffs set in hemlock trees and garnished with ferns.
Within a stone’s throw is Russell Stone. The U.S. Capitol Visitor Center, the University of Virginia at Charlottesville and the Philadelphia Museum of Art all bear silent ties to pits on the mountaintop behind the quarry office—and to the sandstone, the same Homewood Sandstone that’s down the road at lonely Bilger’s Rocks.
Narrow waves vs broad onesInto the office, past the sandstone counter and Dan Russell’s whitetail buck mounts and hearty
greeting, then down into the pit with host Ken Boris I went. A world of creamy white stone spread out around us. “We are 20 feet below the surface,” Boris told me.
Ken provided a brief overview of the surrounding geology that yielded the prized stone. Coal was a presence, with strip mining evident along the road south of Du Bois and a minor deposit scattered over the upper edge of the quarry. On one corner of the pit, the forces of erosion on the high ground degraded the quality of the sandstone, forcing the stone harvest underground. Aspen and fire cherry and red maple flourished.
He pointed out a wondrous slab marked with a wavy grain. “This comes at a higher price,” he said of the markings. The University of Virginia examined the aesthetics of this grain meticulously for their purchase, so far as to select narrow waves over broad ones.
Such diverse links notwithstanding, the sandstone of Russell Stone reaffirms Central Pennsylvania. At Ole Bull State Park, their sandstone built a grand comfort station of pink, tan and white blocks. Poe Valley State Park has contracted for a new office. This stone is upgrading high-profile places permanently.
New push for local productsMike Twigg, section chief of architectural design with the DCNR, cites a new push for local products in their projects. When state architects consider a project, they look at native material in the vicinity. They use it to fuse environment and park.
This ties in with history. The Civilian Conservation Corps of Great Depression years built many state park structures using readily available material. Their rustic picnic shelter floor, built of native flagstone and polished by generations of footfalls, remains at Ole Bull. “We want to continue where the CCC left off,” Twigg explains.
Not all sandstone is alike, and architects recognize this. There is absorption measurement to consider, and compressive strength. Cycles of rainy weather call for a stone with a low absorption measurement, meaning that it sheds water rather than absorbing it. Building a dam, however, requires high compressive strength, so that the stone resists stress while lying beneath other stone.
Russell Stone products grade out well technically. Stone from its Eagle Ridge quarry yields an absorption figure of 1.18, nearly 50 percent below a typical liquid-absorbing value. The same stone boasts a compressive strength figure of 20,000, near the known upper limit.
Such qualities led to the building of famous structures such as Princeton’s University Chapel and Pitt’s Cathedral of Learning. These ventures are part of a lengthy history that began in the mid-1800s, when this stone was referred to simply as Curwensville Sandstone, for the nearby town. The quarries closed in the Depression era, to reopen as Russell Stone in 2002.
Newer, less laborious operation
Operations here that employed hundreds of laborers 90 years ago now produce sandstone in a lean, clean fashion. C-4 explosive splits off neat slabs of undamaged sandstone, reducing labor. Imposing sawblades break it up. What residual material remains is cycled into other uses such as erosion control that demand smaller chunks of stone.
Homewood Sandstone has a long history predating its cultural one. Before it became the Philadelphia Museum of Art steps that Rocky Balboa ran up—absolutely true—it was identified geologically in Homewood, a location in Beaver County. Its history then extends 300 million more years.
The hayscented ferns of Bilger’s Rocks grow on the extinct beach of the extinct Iapetus Sea. Successive episodes of sedimentary overlay and compacting converted loose sand into solid rock. This marine origin explains the decidedly beach-like colors of stone that Russell Stone markets—pinks, tans, creams.
On my way back from the mountain, I visited State College—Geology 101—and stopped at the Nittany Lion Shrine. Graduates were taking turns climbing atop the tawny mountain lion for photo ops. The beast crouched atop a Central Pennsylvania mountain ledge recreated with Russell Stone’s PA-affirming sandstone.
Bill Rozday writes frequently about aspects of mountain Pennsylvania.