Text reads:
"When we try to pick out anything by itself, we find it hitched to everything else in the Universe."
- John Muir, 1911,
My First Summer in the Sierra
John Muir National Historic Site
Martinez, California"
There is also a similar refrigerator magnet with Muir's famous "The clearest way into the Universe" quote and the 1964 postage stamp.
Also available from John Muir National Historic Site: bookmarks with this stamp.
Muir was previously honored with a 5 cent postage stamp in 1964.