The Outdoors, One Letter at a Time. Every puzzle in this book is a line from a great naturalist or a fact about the natural world, set in a simple letter code: John Muir in the high Sierra, Thoreau at Walden Pond, John Burroughs in the fields, and the turning seasons from the first spring wildflowers to the first snow. Each quotation was checked against its book, and each fact against two reliable sources.
When a writer is quoted, the name is in code too, so it can help you along. The first puzzles give you three letters to start; by the last part you’re on your own. Every answer is in the back.