If industrial man continues to multiply his numbers and expand his operations he will succeed in his apparent intention, to seal himself off from the natural and isolate himself within a synthetic prison of his own making.

Our modern industrial economy takes a mountain covered with trees, lakes, running streams and transforms it into a mountain of junk, garbage, slime pits, and debris.

I've never yet read a review of one of my own books that I couldn't have written much better myself.

If you feel that you're not ready to die, never fear; nature will give you complete and adequate assistance when the time comes.

I would give ten years off the beginning of my life to see, only once, Tyrannosaurus rex come rearing up from the elms of Central Park, a Morgan police horse screaming in its jaws. We can never have enough of nature.

If the end does not justify the means - what can?

Our job is to record, each in his own way, this world of light and shadow and time that will never come again exactly as it is today.