After three decades of helping save African forests, Mike Fay, a Wildlife Conservation Soci­ety biologist and National Geographic Soci­ety explorer-in-residence, now has redwoods in his blood.

On day 323 of the transect, in Jedediah Smith Redwoods State Park, I dropped over a log 18 feet in diameter into an abyss of giant botanical pickup sticks, deadfall that had piled up amid the ...

Redwood trees, in particular, were valued for their timber — not for their towering beauty or environmental importance. That began to change in 1964, when the July issue of National Geographic ...