State
Fossil sites in Pennsylvania
Pennsylvania's two accessible fossil sites are modest by comparison to neighboring states, but both offer collectors a local option without crossing state lines: a fee-based Devonian marine pit in the center of the state, and a Carboniferous plant exposure in the west.
Montour Preserve Fossil Pit near Danville exposes Devonian marine limestone where collecting of trilobites, brachiopods, gastropods, and crinoids is permitted for a fee. The site is managed by PPL Corporation as part of a broader nature preserve. Productivity varies with recent digging and weather, but the site consistently produces identifiable material across a range of Devonian invertebrate groups. Bring your own tools; hammer and chisel work is permitted.
The Ambridge area in western Pennsylvania exposes Carboniferous-age plant material from the Pennsylvania System, the geological period named for the state's coal-bearing strata. The plant exposures are best treated as a viewing site rather than an active collecting locality. Neither site approaches the output of Ohio's Caesar Creek or Maryland's Calvert Cliffs, but both are within a day's drive for collectors based in Philadelphia or Pittsburgh who want to find something locally.
4 fossil sites

Ambridge Fossil Hunting Guide
Pennsylvania, United States
Plant Fossils, Marine Invertebrate Fossils

Mahantango Creek (Snyder County) Fossil Hunting Guide
Pennsylvania, United States
Brachiopods, Trilobites, Corals, Cephalopods

Montour Preserve Fossil Pit Fossil Hunting Guide
Pennsylvania, United States
Trilobites, Brachiopods, Gastropods, Crinoids

St. Clair Fern Fossils Hunting Guide
Pennsylvania, United States
Fossil ferns (Alethopteris), Fossil ferns (Neuropteris), Fossil ferns (Pecopteris), Sphenophyllum