by Mike Anderson and Scott Stephens, Ph.D.
Imagine that you are DU's director of conservation programs. Board a Northwest Airlines A320 bound for Minneapolis from Edmonton, Alberta, on a sunny day in May. In just under three hours you'll fly a narrow transect across the Prairie Pothole Region—North America's duck factory. These 300,000 square miles of farmlands and wetlands support more than half the continent's breeding ducks.
As the jetliner climbs and banks east from Edmonton, you cast your eyes north to the horizon and glimpse the patchwork of dark and light green marking the southern fringe of Canada's vast boreal forest. This has been a land of ducks and trees for thousands of years but is now a place of rapid resource development. Directly below the plane lie the aspen parklands—a matrix of aspen and willow clumps, grazing land, and fields dotted with thousands of small wetlands that reflect the rising sun. You can't see the ducks from up here, but this is mallard country. Where the wetlands are deeper and fringed with cattail, it is also canvasback country.
As the jetliner levels off near 37,000 feet you can see below the climate-driven transition from forest to prairie. This high up, approaching the Alberta-Saskatchewan border, you can take in all at once the gradual change from mostly trees to mostly grass. Everywhere there are still potholes—remnants of the last glacial scouring. Most of the ponds are small; some lie in dense concentrations, more are sparsely scattered; many have been drained or filled.
You notice that the landform is anything but uniform. Patches of higher, hilly ground—often with less tillage and more wetlands—stand out from the flatter, intensively farmed plains. As you approach southern Saskatchewan, the largest of these clumps of hills takes the form of a long, mostly continuous range stretching to the southern horizon (to South Dakota, in fact, if you could see that far). This is the famed Missouri Coteau, an awesome landscape that comprises the single greatest sweep of native grassland and wetlands in the world. In wet years this is truly the best of the duck factory, where wigeon, gadwalls, pintails, and others teem, but in many years much of the coteau is dry.
Floating on south along the eastern edge of the hills, you cross the 49th parallel, separating Saskatchewan from North Dakota. The landforms look much the same; here the national boundary is clearly an arbitrary human imprint. Soon you notice that more frequent blocks of grassland appear in the farmland matrix—the product of USDA's Conservation Reserve Program (CRP)—totaling several million acres in the Dakotas alone. At the same time, the drift plain stretching eastward shows the marks of long-standing agricultural use. Except for CRP fields, and large federally protected wetlands, this is intensively farmed country and vast areas have been ditched, drained, and plowed for human purposes.