Fossil Hunting in Pennsylvania

Just pointing to American Geode and their fossil hunting expedition along PA Route 15, which yielded some Devonian plant specimens and an encounter with a family of bears (video at the link.) Coral Caverns in south-central PA is unfortunately no longer open to the public, but was formed from Devonian corals. Coral from this era also shows that the length of the day on Earth used to be shorter - angular momentum has been lost to tidal drag since then, which is cool in and of itself but also gives us an additional clock for the age of the planet. Additional PA geology nerdiness here; you'll see that the Appalachians used to be the same range as the Atlas Mountains in northwestern Africa, and indeed there are even more geodes in Morocco owing to the drier conditions.

Pennsylvania geology remains under-rated.