When the first settlers came to the United States, they found the country teeming with waterfowl; the district along the Atlantic coast seemed to have an inexhaustible supply of ducks and geese. But in later years, when emigrants pushed westward and crossed the Mississippi, they discovered that the flocks of the coast were as nothing to the countless throngs that passed each spring and fall over the western prairies.

No other duck, except the black duck, seems to have cared to nest in any numbers east of Hudson Bay, and enormous flocks of ducks reported by the early settlers, in the fall migration, were not eastern-bred birds, but were travelers from the interior of the North American continent, where tracts of country furnishing exactly the conditions desired by ducks and geese were to be measured by square miles instead of acres.

The prairie districts of central Canada, comprising large portions of Manitoba, Saskatchewan and Alberta, have been and still are the “duck paradise.”

The so-called “prairie region” of the United States then extended from Canada into Montana, North Dakota and South Dakota, Minnesota, Iowa, Illinois and northwestern Indiana.

And so much of it was occupied by lakes and marshes — northern Indiana, a wide strip of northern Illinois, another strip of northern Iowa, and thence northward toward the Arctic Ocean — that it was crowded with breeding ducks and geese. It abounded in lakes, ponds, sloughs and marshes, which furnished ideal nesting conditions and a plentiful supply of food, and years ago every available nook was preempted by waterfowl.

But the “prairies” were disturbed. The Northern Pacific and other railroads cut across its southern border in Minnesota and North Dakota, a north and south line was run to Winnipeg, and other shorter branches were built.

A still more severe blow was dealt the waterfowl when the Canadian Pacific Railroad crossed, between Winnipeg and the Rocky Mountains, the finest duck-breeding grounds on the continent. Their last stronghold was finally invaded by the Grand Trunk Railroad, and soon the great colonies of northern Alberta and northern Saskatchewan were things of the past.

It soon became apparent that in a few years neither the United States nor southern Canada would have any large breeding places of those species of ducks which were most highly valued for sport and for the table.

Soon the lower half of this vast region in the United States, formerly held in undisturbed possessions by waterfowl, became almost overnight an almost continuous farm, and the millions of waterfowl that once bred there were replaced by millions of human beings.

In the last century, agriculture took its toll on prairie potholes.

It's estimated that about half of the small, shallow wetlands in North Dakota and South Dakota have been drained for agricultural production. And when you get over to Minnesota and Iowa, upwards of 95 percent plus of the small, shallow wetlands have been drained.

Only an estimated 40 to 50 percent of the region's original prairie pothole wetlands remain undrained today.

The Prairie Pothole Region's salvation in the United States has been the Conservation Reserve Program, created in 1985. CRP has created conditions which has produced and sustained millions of ducks and grassland birds in the Prairie Pothole Region of North Dakota, South Dakota and northeastern Montana.

CRP grassland in the Prairie Pothole Region in North Dakota, South Dakota and northeastern Montana has helped produce 26 million ducks (2 million annually) between 1992 and 2004, representing five species (mallard, gadwall, blue-winged teal, shoveler and pintail).

This represents an estimated 30 percent increase in duck production compared to that expected from the same area without CRP cover.

In wet years, 70 percent of North America's waterfowl population originates from the Prairie Pothole Region.

Encompassing 34.7 million acres, CRP is the nation's largest and oldest voluntary conservation program.