As the Izaak Walton League begins its second century, we asked experts about the coming challenges and priorities for conservation. Elizabeth D. Hilborn, veterinarian and environmental scientist, tells us about the small changes that make a big difference.

Next year, we will remember the creation of the Upper Mississippi River National Wildlife and Fish Refuge, which the Izaak Walton League forged in 1924. The League leveraged its growing membership and influence to convince Congress, the White House and four states to set aside the rich wetlands along the river. But as noted water expert Chris Jones explains, many challenges remain. Here is his take on the Mississippi, past and present.