The outer fossils are one of the world's amazing excursions to see Devonian fossils in their natural "habitat." We only offer this hike in the late summer and fall when the upper gates of the McAlpine Dam are closed. This 3-hour hike is moderately rugged on uneven limestone ledges and without shade, so wear a hat. Use enclosed shoes and bring water. You will do a little wading; the worst is about two feet deep with a moderate current. We will explore the geology, history, and river dynamics & engineering of the dam and 1870 railroad bridge. Watch for birds and other wildlife. Meet at the Interpretive Center 15 minutes early to sign the waiver. The hike is for anyone over age 12.