The Upper Kellwasser Event (UKE) represents one of the most significant Phanerozoic mass extinctions, eliminating ~50% of marine genera at the Late Devonian Frasnian-Famennian boundary. In the northern Appalachian Basin, this event is preserved as the Point Gratiot Bed (PGB), a decimeter-thick organic-rich black shale, well documented from the outcrop belt in western New York. This study documents the UKE in cores from northwestern Pennsylvania, eastern Ohio, and western West Virginia housed at state repositories, extending the known occurrence across the basin. Identification utilized diagnostic criteria from New York outcrops: stratigraphic position, distinctive molybdenum (Mo) profiles (high basally, decreasing upsection), consistently low uranium, decreasing Mo/TOC ratios, and decreasing framboid diameters upsection. Outside of New York, the candidate PGB is represented by a black shale that ranges in thickness from 0.5 – 54 cm. The bed sits below a decimeter thick unit of gray shale which contains abundant cm-scale carbonate nodules, like the Beaver Meadow Member in New York. This unit is overlain by black Huron/Dunkirk shale. X-ray fluorescence analysis of the bed revealed Mo values of 25 – 120 ppm in the basal portion decreasing to 1 – 27 ppm upsection, while uranium remained consistently low (~ 7 ppm). Total organic carbon increased upsection from an average of 7.4 % to 10.6 %, yielding decreasing average Mo/TOC ratios from 8.4 to 1.1. These patterns match those observed within the PGB across the New York State outcrop belt. These patterns present a paradox: molybdenum depletion coincides with evidence for intensifying anoxia (increasing TOC, decreasing framboids, diminishing bioturbation, increasing pyrite). This rules out improving oxygenation and points to either basin restriction ("basin reservoir effect") or global metal drawdown during an oceanic anoxic event (OAE). Cross-basin comparisons provide evidence of both mechanisms. Mo-enriched novaculite in the Arkansas Novaculite (Ouachita Trough) argues for a global ocean sink. However, a systematic gradient emerges: the highly restricted Illinois Basin shows minimal Mo enrichment, the semi-restricted Appalachian Basin shows moderate enrichment, and the unrestricted Oklahoma Basin shows greater (though still subdued) enrichment. These findings demonstrate that global OAEs are differentially expressed depending on basin restriction, with progressively restricted basins showing progressively muted signals. This highlights the necessity of multi-basin, high-resolution studies to distinguish global from regional environmental signals during mass extinction events.