Preserving the Slough

By Abby Hade Terpestra on June 19, 2023 in Blog

View from the road of the Brenton Slough with old railroad bridge in the distance

^{Birding enthusiasts and nature lovers often flock to see this view from the gravel road that intersects the Brenton Slough. In the distance, an old railroad bridge is visible. Photo by Erica Place/INHF}

Sitting on the edge of Polk and Dallas Counties, with 1,113 acres of wetlands, woodlands and oak savanna, the gravel road running through Brenton Slough is a mecca for birders, naturalists and nature photographers. Often the road’s edge is lined with folks peering into the private property to glimpse where Sandhill Cranes nest, tiger salamanders skitter, and soft shelled turtles as big as platters bask.

Back in the day, part of the Department of Natural Resources annual display at the Iowa State Fair was a live exhibit of Iowa’s wildlife. “This is where they’d go to catch turtles and snakes,” shares Bill Brenton. “They’d return them afterwards. They knew they could find lots of good examples here.”

The valley that the Brenton Slough property sits in is at the very southern end of the Prairie Pothole Region and was formed by the Des Moines Lobe of the Wisconsinan Glacier over 12,000 years ago. The glacier picked up sediment as it carved through the earth and then, as it receded through the bend in valley, meltwater deposited sand bars on a massive scale. Those sand bars created a wetland stream corridor filled with ridges and hills — a unique place where forest, prairie, river and wetland systems intermingle.

The main body of water on the property meets the national definition of a slough — one of only fifteen mapped as such in Iowa. The 52 acres of water there tends to be stagnant or flowing slowly on a seasonal basis, with its deepest point only around three feet.

“At the right time of year, from the edge of the water up the shoreline about five feet is ringed with frogs,” said Bill. “The chorus is just astounding.”

Beaver Creek and its oxbows are a dynamic part the property, prone to seasonal flooding that leaves the area spongy or at times like a backwater marsh. Its seclusion and the proliferation of wildlife there led W. Harold Brenton to have it designated as a Game Refuge in the early 1900s, right as the conservation movement began.

Over time, Bill has noted the fluctuations of wildlife populations at the slough. “When I was a kid, it was all Snows and Blues [geese],” he said. “The skies and ponds were filled with white. Then, twenty years ago, Canada geese started taking over. Now the Snows and Blues are coming back.”

“Mixed habitat types make for maximum bird diversity,” said Ty Smedes, an area wildlife photographer and bird enthusiast who has long admired Brenton Slough through his lens. “It’s great to see that not just the water but also the surrounding upland will be protected. Having land adjacent keeps predators from working the edges of the wetland, raiding nests of waterfowls and birds like pheasants that would have nowhere else to nest.”

A Sandhill Crane and two colts. Photo by Ty Smedes

^{A Sandhill Crane and her two colts browse for food at the Brenton Slough. Photo by Ty Smedes}

The Brenton family has long used the property as a playground and retreat. W. Harold Brenton inherited the land from his father, Charles, and his uncle, Clyde. Charles and Clyde purchased the property and additional surrounding 900 acres from two lumber companies and an individual from New York State, Mr. Ingersoll. The Brenton family has farmed the land for over a hundred years. Currently it is owned by the family members of Charles Robert “Bob” Brenton and Junius Clyde “Buz” Brenton, who are the sons of W. Harold Brenton and Etta Spurgeon Brenton, operating as Brenton Brothers Inc. and Brenton Farms Inc. Bill Brenton, son of Bob, has been the operating farm manager for decades.

“Dad would come tour the farms every weekend,” Bill remembers. “We’d tour the cattle feed lot, the hog farm, the crops, shake hands and say hello to all the men, ask about their families. He always said that was his golf game.” Bob kept touring the farms with Bill every Saturday until about ten years ago.

Ken, Bill’s cousin, grew up nearby in Dallas Center. “I’d run through the cornfield out back to get over there,” Ken remembers. “We’d go out, pick up eggs and go get bags of sausages and hamburger from the Granger meat market, all from the farms.”

They both remember their grandfather, Harold, bringing folks to the slough for duck hunting or lobster boils. “Harold was the Treasurer of the National Republican Party, and Bob was the President of the American Bankers Association,” Ken shared. “This was a place to bring people together, get to know them, and do a little business.”

Bill adds, “When my kids were growing up we’d camp out there in the summer and have ice skating parties in the winter. We’d collect whatever skates we could find for friends who would come. It was a great place for that.”

The surrounding area has been seeing significant change as development from Johnston, Grimes, Granger and Urbandale surge around its borders. But standing in the property’s interior, sheltered by the undulations of glacial moraine and the canopy of mature trees, nature surrounds you fully.

Map of the Brenton Slough

Thirty-two members of the Brenton family have been contemplating for years what the best future of the property would be. “It became apparent to the family that the land should be held in perpetuity by an entity that can assure its preservation,” Bill said. “We wanted a partner that could assure its preservation and provide it to the community as an asset to be protected and experienced.”

“We were honored to be invited to the table,” says Joe McGovern, President of Iowa Natural Heritage Foundation. “This is a very special place with a rich history, in an area of the state seeing rapid changes to the landscape.”

An agreement was reached late in the winter of 2023. This July, Iowa Natural Heritage Foundation will be purchasing the property from the Brenton family with a plan to transfer ownership and management to Polk County Conservation following fundraising. Brenton Slough will eventually be open to the public once all the funding is in place.

“Ken’s and my family have owned [Brenton Slough] together since the ‘90s,” said Bill Brenton. “We wanted to make it into a park, keep it as natural as we can and keep as much of the wildlife as we can. It is important to us to preserve the naturalness, the rustic-ness of it. We wanted to preserve this forever and this is a great way to do it.”

A project of this size and scope comes with considerable cost – it will take $8 million to secure the property. Already, Polk County Conservation has identified $3 million in funding, and a generous donor has pledged an additional $500 thousand. Iowa Natural Heritage Foundation is assisting with fundraising efforts with a goal to raise the remaining $4.5 million through a public donation campaign and grants.

“Public show of support is crucial in leveraging fundraising at the state and federal level,” said Heather Jobst, Senior Land Protection Facilitator at INHF. “A donor campaign will increase our chances at scoring well and leveraging these competitive dollars.” INHF’s goal is to have an additional $3 million in public support pledged by Labor Day 2023.

“This gives a chance for people to be directly involved in protecting a place where habitat is crucial to conserve,” adds Stacie Couvillon, INHF’s Planned Giving and Major Gifts Officer. “Brenton Slough is already a place people travel to see, even if they can currently only do so from the public road. To be able to invite quiet recreation into it while preserving this ecosystem is quite a treat.”

Polk County Conservation is working to finalize their vision of what Brenton Slough will look like in the future. Currently the staff is planning to facilitate light recreation through mowed hiking paths, infrastructure for birders, and occasional volunteer or educational events. A mixed-use trail is likely to run along the property as part of the larger trail development plans in the area. Even with these additions, Polk County Conservation will manage Brenton Slough with the goal of maintaining, increasing and improving wildlife habitat.

“This is nature being nature,” said Rich Leopold, director of Polk County Conservation. “We will let it thrive on its own where appropriate, and in other areas we’ll carefully manage the land to restore or improve it. It’s a vibrant, wild place we get to experience right here.”

“It is important to get kids interested in science and biology,” said Ken Brenton. “That way they become interested in protecting this, protecting nature. We’d like young kids to be able to visit this place and maybe get interested, take a science course.”

In a booklet detailing the land and wildlife of Brenton Slough, put together in 2020 by Chuck Brenton, Bill’s son, he says, “The way I see it...the land of Iowa has been extremely generous to the Brenton family for well over 150 years, and now is our time to give back.”

“The Brenton family has taken good care of the land,” said McGovern. “We are pleased that this will continue under Polk County Conservation ownership in perpetuity.”

In a county undergoing such rapid change, conservation of properties with existing quality wildlife habitat, especially such a large parcel, is a rare and wondrous opportunity. Brenton Slough will forever continue to be, thanks to the conservation desires of the Brenton family, a gem of central Iowa and a birder’s paradise.