Hooray for America's nature. One big reason it's there to treasure: the National Wildlife Refuge System, the world's premier network of public lands devoted to wildlife conservation. The Refuge System turns 113 on March 14.

Wait! Think before you aim that camera at a national wildlife refuge. It may be habit-forming. That’s been true for four standout nature photographers – each hooked on prowling a favorite refuge in hopes of locking eyes with a bird or fox, capturing light and color, and probing the mystery of our animal natures.
 

A frolicsome sea otter, noisy (and stinky) sea lions, and hundreds of migrating pelicans were among the first inhabitants to greet us as the Elkhorn Slough Safari (a 27 ft. pontoon boat) motored slowly away from the harbor. 

Although Wisconsin’s Horicon Marsh is hugely visited each year, its size means that it is easy to feel alone in the wilderness. Birds of all sizes and kinds wheel and cry over this gigantic wildlife preserve, filling the blue sky with their wings. Bullfrogs croak from the cattails, and butterflies dance across the marsh. This is the ultimate destination for any nature lover. But first you have to get there!