-Three months of camp life on Lake Tahoe would restore an Egyptian mummy to his pristine vigor, and give him an appetite like an alligator. I do not mean the oldest and driest mummies, of course, but the fresher ones. The air up there in the clouds is very pure and fine, bracing and delicious. And why shouldn't it be?--it is the same the angels breathe.---Mark Twain, Roughing It

Here are more than 3,700 quotations in 143 categories--from Acid Rain to Zoos--that provide a comprehensive collection of the wise and witty observations about our natural environment. The...