“Phoebe Snow” and the ice sheets: how the Delaware, Lackawanna & Western railroad adapted its Scranton-to-Binghamton route to a glacially modified landscape, northeastern Pennsylvania and south-central New York
BRAUN, Duane D., Geography and Earth Science Department, Bloomsburg University, Bloomsburg, PA 17815; INNERS, Jon D., (retired) Pennsylvania Geological Survey, 3240 Schoolhouse Rd, Middletown, PA 17057; and KOVACH, Jim, Skelly and Loy, Inc., 2601 North Front St., Harrisburg, PA 17110.
Beginning in the mid-19th century the major transport route of Lackawanna Valley anthracite to Buffalo and the Great Lakes was that of the Delaware, Lackawanna & Western (DL&W) Railroad from Scranton northward across the Allegheny Plateau through Binghamton, NY. This route took advantage of a deep, 24-mile-long sluiceway cut by glacial and meltwater erosion through the east-west drainage divide between the upper Susquehanna River and Tunkhannock Creek in Susquehanna and northern Wyoming Counties, PA.
Formed by repeated advance and retreat of continental ice sheets, the “Summit” sluiceway is now occupied by north-flowing Salt Lick Creek and south-flowing Martins Creek. During the Pleistocene, the col between the two creeks was lowered by as much as 600 feet, mainly by overflow from proglacial lakes repeatedly impounded in the valley of Salt Lick Creek. Late Wisconsinan hanging deltas at the mouths of tributary valleys just north of the Summit divide are graded to the elevation of the floor of the spillway.
Recognition of the easy gradient provided by the Summit sluiceway began with the earliest Scranton-to-Binghamton railroad survey in the 1830’s. Railroad construction by an immediate forerunner of the DL&W took place mainly between 1849 and 1851, with the route north of Tunkhannock Creek following the gentle gradients of the sluiceway and that south of the creek constructed over hilly topography into Scranton. From 1912 to 1915 the DL&W undertook a massive realignment. Although generally following the old route, the new alignment cut off several miles, lowered both north- and southbound gradients, and greatly reduced the curvature and vertical “rise and fall.” It entered the glacial sluiceway at the north end of the great Tunkhannock Viaduct, about 180 feet above the old crossing of Tunkhannock Creek, and for much of the distance northward (except where it crossed Martins Creek on another high viaduct) clung to the valley sides in a series of deep cuts through Upper Devonian Catskill sandstones and shales.
Although the DL&W—“the Route of Phoebe Snow”—and its successor Erie-Lackawanna Railroad passed from the scene more than 20 years ago and traffic on the Scranton-to-Binghamton line is now but a fraction of what it once was, the “Summit Cutoff” and its monumental viaducts still stand as testaments to creative engineering applied to natural, geohydrological pathways.
Poster paper presented at the 34th Annual Meeting of the Northeastern Section Geological Society of America, Providence, RI, March 22, 1999.
Braun, D. D., Inners, Jon D., and Kovach, J., 1999, “Phoebe Snow” and the ice sheets: how the Delaware, Lackawanna & Western Railroad adapted its Scranton-to-Binghamton route to a glacially modified landscape, northeastern Pennsylvania and south-central New York: Geological Society of America Abstracts with Programs, v. 31, no. 2, p. 6.