The Wild Trees by Richard Preston

An astonishing account of several unschooled naturalists obsessed with finding the largest tree on Earth.  Hiking miles into unmapped, unexplored areas of the California Redwood forests, they access areas so remote & inaccessible, no human save possibly ancient Native Americans has ever been there.  To fuel their passion, they fashion climbing apparatus and ascend hundreds of feet into the forest canopy, going as far as living atop the trees for weeks to find & observe new and undocumented species of plants & animals - a virtual Great Barrier Reef of life which has evolved entirely in the sky.  Complete with maps and drawings, this book of exploration, danger, persistance, and human folly is an unexpected joy to read, proving that there are still wonders of nature we have yet to uncover.