The Cottonwood Slough
Editor’s Note: This story is revised from the March/April 2008 issue of South Dakota Magazine. To order a copy or to subscribe, call 800-456-5117.
Marvin and Connie Piotter felt their 400-acre Roberts County farm was unusual when they bought it in the early 1970s, and they later found out why.
“Sometimes I would make a cup of coffee and go out above the lake at 4:30 or 5:00 in the morning and listen to the world wake up,” said Connie. She listened to the songbirds, saw ducks and geese lifting off from their overnight stay and spotted deer as they looked for daytime nesting places. Nature also has a violent side. She once saw a bald eagle lift an adult Canada goose off the lake and fly away with it.
The Piotters’ native grass pasture is on the southeastern border of Lake Bde-Sake (Dakota for “Dirty Water”), but Marvin and Connie eventually learned that the lake has other names. Eons ago, the 11-mile stretch of water was part of Lake Agassiz, the world’s largest glacial lake. Only archeologists and Roberts County residents are likely to know that. Local people call the area Cottonwood Slough or Dry Run.
The lakes eventually drain into Jim Crick below the Piotters’ farm; Jim Crick flows south for a mile and feeds into Lake Traverse, which flows northward into North Dakota and the Red River Valley. “They drink our water in Grand Forks,” said Marvin.
Canadians far to the north might also drink rainwater and snowmelt that begins to collect in the Cottonwood Slough, because the slough constitutes the southern tip of the massive Hudson Bay watershed.
All the rest of South Dakota drains into the Gulf of Mexico, via the Missouri and Mississippi rivers. The two watersheds are separated by one of the North America’s five great continental divides — ranges of hills and mountains that send the continent’s waters to the Pacific, Arctic and Atlantic oceans, and to Hudson Bay and the Gulf of Mexico.
Roberts County citizens are familiar with the geology of the divide, but only a few probably recognized the watershed’s international importance before the National Park Service sent scientists from the University of Colorado to study the site. They concluded that the wetlands were a buffer zone that divided the tall grass prairie from the eastern deciduous forest country. “It is among the top natural areas in this part of the country for concentrating and production of waterfowl,” they concluded, “and one of the best natural riverine wetland complexes remaining…”
Scientists found the rare piping plover, a tiny bird listed on the endangered species list. Further exploration indicated that Native American artifacts and burial sites lay in the hills above the lakes. In 1975 the National Park Service declared the lakes a Natural National Landmark.
The landmarks program identifies unique geological and biological lands owned by either public or private parties. Less than 600 have been found in the entire United States. Cottonwood Slough is one of a dozen such sites in South Dakota. Some others include Sica Hollow, a prairie forest northwest of Sisseton; the Castles, a series of sandstone spires in Harding County; the Fort Randall Eagle Roost, west of Wagner; the Mammoth Site in Hot Springs; and Bijou Hills, north of Platte.
Mike Gallagher, a now-retired NPS staffer who was involved with the National National Landmarks program, said Roberts County farmers and landowners who surround Cottonwood Slough have done an excellent job with the property. “This is a perfect example of what we hoped to achieve. The goal wasn’t to have public ownership of these unique land features, but to work with private owners to preserve and protect the land.”
The Cottonwood Slough begins just east of the little town of Victor, near the North Dakota border, and meanders below farmsteads and cattle pastures before narrowing into the crick and then into Lake Traverse. The Cottonwood valley is about a half-mile wide and constitutes 5,400 acres in total. Its tiny lakes, marshes and potholes are rimmed and intersected with a thick growth of cattails and rushes. The foothills on both sides are thick with cedar, cottonwood, ash and box elder trees.
“The park service just raised our pride in what we already loved,” Connie said. “It should remain wild and natural. I’d hate to see it built up with resorts and lodges.”
Living by the lakes has been entertaining and educational for people like the Piotters. “When we first moved here, I remember watching some young Indian boys playing in the water,” Connie Piotter said. “They would grab onto the gills of these huge carp in the shallow waters, and then they’d ride them a little ways before they’d fall off. It was something to see.”
Several species of fish swim up from the Red River (upriver is south for this country), and they spawn in the Cottonwood Slough. “First come the northerns,” said Marvin. “Then it’s the bullheads and the carp.”
Ducks and geese visit by the thousands in spring and autumn. “It’s not always pleasant to live along the flyway,” Connie said. “The geese have been so thick that they’ve turned the hills white with droppings. We tried to grow sunflowers but the blackbirds just decimated them. There was nothing left to harvest.”
Eagles, rarely seen in Roberts County 30 years ago, are now common. A few are starting to nest in the trees. They are a noble sight, but pesty. “We had cows calving near the slough, and the eagles would fly down and eat the afterbirth when a cow had her calf,” Marvin said. “That would cause the cows to go nuts, but the eagles never did bother the calves.”’
The Piotters graciously share the hills and lakes with others who show an interest. In fact, they’ve signed an agreement with the National Park Service “to protect, use and manage the site in a manner which prevents the destruction or deterioration of its nationally significant problems in managing the area.”
The Piotters raised four daughters and two sons on their Roberts County land, and both of the sons — Matt and Daniel — farm with them. “We want to preserve it for them and for our grandchildren and beyond,” Connie says. “We always knew it was special.”