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Riparian Restoration in the Big Horn Basin


With fully grown Russian olives, heavy machinery is needed to remove them

The gawking began with a couple of drivers on their way somewhere. The men on the work crew paid them no mind and continued using heavy machinery to remove Russian olives along Big Horn River. Soon, the normally quiet road began to fill with more vehicles. Jim Mischke, district conservationist for the Natural Resources Conservation Service (NRCS) Thermopolis field office, who was on site to watch work progress, decided to find out the cause of the continual traffic.

When asked, one of the motorists said, “We’ve never been able to see the river from here before.” It seemed the whole town of Thermopolis, population 3,000, came out for the novelty of the view.

After decades of putting up with invasive species such as Russian olives and salt cedar, many landowners in the Big Horn Basin have decided they have had enough. With help from various groups and organizations, they are slowly reclaiming their land.

For Dee Hillberry, it took at least six years before he was able to get a handle on the hardy invasives. Working on two separate properties, he removed tamarisk, also known as salt cedar, from 200 acres on the Cottonwood Creek and pulled out Russian olives from 100 acres on the Big Horn River.

Despite Hillberry’s dedication and hard work, his portion in riparian restoration is but a small part of an endeavor that involves several projects done in phases over several years, over hundreds of miles, and with numerous partners.

Conservation districts have played a key role administering the grants. Without the folks at districts of Washakie, South Big Horn, Hot Springs, Shoshone, and Powell/Clarks Fork, it would have been almost impossible to make a project of such a large scale reality.

The Wyoming Wildlife & Natural Resources Trust (WWNRT) has contributed $2 million since 2004. The USDA’s NRCS has provided funds through conservation programs, such as Agricultural Management Assistance and the Environmental Quality Incentives Program. Other partners include the local districts of the Wyoming Weed & Pest, Wyoming Game & Fish; Bureau of Land Management; and The Nature Conservancy.

“No single agency could do it themselves,” said Amy Anderson, habitat extension biologist with the Wyoming Game and Fish in Worland. “This work would not have continued without the solid partnerships that we have formed with all of the agencies, entities and landowners throughout the Basin.”

The Big Horn Basin is about 100 miles wide. The largest cities in the basin include Cody, Thermopolis, Worland, and Powell. It is drained to the north by tributaries of the Big Horn River, which enters the basin from the south.

The Big Horn River flows through the center of Big Horn County with confluences of the Greybull, Shoshone and No Wood rivers. The majority of land adjacent to these rivers is private. These areas are critical to the local environment and economy.

Originally brought to the western states in the 1800s as an ornamental and later recommended as windbreaks during the Dust Bowl, thousands of Russian olives were planted by landowners, and conservation and wildlife agencies.

These tough fast-spreading trees choked out the native vegetation. Native cottonwoods, willows, and fruit-bearing shrubs could not compete with the aggressive and highly adaptable Russian olives. With their dense thickets, they created difficulties for those looking for a path to the water. Hillberry said, “They were so heavy, so dense, we couldn’t ride our saddle horse down to the river bed.”

In addition to restricting human and wildlife land use, the Russian olives bring a whole list of problems which outweigh their benefits, Anderson said. “They threaten the biodiversity of the Big Horn Basin.”

Salt cedar was introduced also as an ornamental and later used as windbreaks and shade, as well as to help control erosion along stream banks. Designated as one of the top 10 noxious weeds in the U.S., salt cedar displaces native trees, shrubs, grasses, and uses more groundwater than native plants. It provides little value to wildlife as a food source. Population and diversity of many animals, such as birds, insects, also decline in areas of infestation.

Other invasive species throughout the Big Horn Basin include the Russian knapweed, spotted knapweed and hoary cress, Canadian thistle, and leafy splurge, to name a few. They are detrimental to the land and render it unproductive for agriculture and recreation, Anderson said. These invasives also increase the salinity of the soil, widen floodplains, and invade irrigation canals.

However, when the invasives are removed, the land seems to undergo a transformation. Anderson said, “We saw waterfowl and songbirds return.” Since clearing his land of invasive species, Hillberry has seen a revival of bird population. “I’ve got pheasants like I’ve never seen before. A friend and I went hunting and got three a piece (within minutes) and we were done,” he said.

The key to Russian olive removal is to do it when the plants are small, said Lindsey Woodward, supervisor of the Hot Springs County Weed & Pest Control District. “It is cheaper and easier to do it then,” she said.

With larger full grown trees, heavy machinery such as a tree shear attached to a tractor may need to be called in, or a timber axe connected to a skid steer.

To try to remove the trees any other way can break one’s determination as Michael Wright and his wife Jacky discovered. About 10 years ago, they went after the problem on their property by East River Road by attempting to eliminate the smaller trees as they popped up. Using a pruning saw and an herbicide to kill the roots, the Wrights did the best they could the only way they were able.

“However, we looked around the property and it was surrounded, all around the river bank by very large trees, and we had no practical way of eradicating them. We took down a few with a chainsaw, but its backbreaking miserable work.

We didn’t have any large scale equipment and no one, to our knowledge, was contracting to remove Russian olive on a large scale. That’s why the NRCS program was a great opportunity for us,” Michael Wright said.

“We had 30 acres we were not able to get to. The Russian olives had crowded everything out,” he said.

After studying options with Mischke and Dawn Peil, a rangeland management specialist in the NRCS Thermopolis field office, Michael Wright decided to use a shredder machine to shred the trees instead of pulling them out.

He said the multi-agency approach toward invasives did what he could not do on his own years ago.

Tamarisk on the Gooseberry Creek

The multi-agency collaborative efforSprayTameriskWeb.JPGt began in 2003, when Rory Karhu, who was working for the Game & Fish in Worland, attended a Tamarisk Coalition meeting in Colorado. Tamarisk was, as it is now, a significant invasive species in Wyoming. “We started with tamarisk as an important invasive species to control. It had no forage value. Back then, the Russian olives were not on the invasives list,” he said. “They were still being sold in Wyoming.”

After deciding to make the Gooseberry Creek, a tributary to the Big Horn River, a priority, Karhu spent that summer on horseback. Using a weed sprayer and with two carbon dioxide canisters – one on each side of the horse – he worked on 50 miles on the upper creek. “We focused on one drainage, from top to bottom, to see if we could eradicate it,” he said.

Writing grants and using many different program funding sources, Karhu had help from Tori Dietz, director of the Washakie County Conservation District. “Washakie County Conservation District held the grant funds. Our first grant was with the newly created Wyoming Wildlife & Natural Resources Trust,” he said.

It was the purchase of a timber axe which got Dietz involved. “We knew we had to do more than just making it available for producers and we later gave it to the (local) weed and pest district” As the flow through organization, the conservation district applies for and administers all the grants or as Karhu said, “Tori made sure things didn’t get dropped.”

In 2005, Karhu joined the NRCS as a biologist and in 2006, he returned to Worland as district conservationist. Now district conservationist for the NRCS Powell field office, Karhu is pleased with his work which has been taken up with others. “We have made a significant dent. Landowners could now manage the tamarisk on their own by never letting it go back to the original infestation.”

Watershed Approach

Working together: From left, Jim Mischke, NRCS; Lindsey Woodward, Wyoming Weed & Pest; Amy Anderson, Wyoming Game & Fish; Dawn Peil, NRCS.

To better utilize money, resources, and time, Wyoming NRCS and partners began systematically focusing on high priority locations before moving on to another waterway, Karhu said. This watershed approach pushes the invasives down the tributaries and eliminates backtracking and reworking on previously done waterways. 

Laura Galloway, district conservationist for the NRCS Worland field office said, “We didn’t want to start on the Big Horn River until we took care of the tributaries going into it.” She said the seed source needed to be removed as part of the top down approach. “We finished the majority of the acres needing cleaned up on Gooseberry Creek, Cottonwood Creek, and Nowood River.”

According to Anderson, the team of cooperators is currently at work on eight watersheds throughout the Big Horn Basin.

The Nowood River, which spans over the counties of Big Horn and Washakie, is one of three priority drainages
NRCS Greybull field office. The other two are Shell Creek and the Greybull River.

Bush, a district conservationist, said NRCS began using AMA funding for Russian olive and salt cedar removal for the Nowood River in 2008. The Nowood River watershed covers 1,287,000 acres and is habitat to moose, mule deer, elk and a variety of other species.

In 2009, work began with Russian olive and tamarisk removal on the Shoshone and Clarks Fork rivers in Park County. This project, like many others, included dozens of landowners and partners, but also included a partnership with Powell High School. Students studied water yield, water quality, soils, vegetation and wildlife responses to habitat improvements. Wildlife has returned, including pheasants, turkeys, waterfowl, deer and songbirds.

From 2009 to 2012, in only two years, Anderson said the Cottonwood Creek has had 100% treatment from top to bottom of the watershed. “It is a major success. That effort was completed with a landowner-driven watershed improvement district, Game and Fish, Weed and Pest, NRCS. 2,000 acres,” she said.

In the Big Horn Basin, Anderson estimated that about 13,000 acres have been treated.


Web2012 vs 2009 Ro Control Shoshone River pdf_Page_1
Comparison of 2012 after Russian olive removal with 2009 infestation.

Once the Russian Olives have been removed, there remains continued monitoring and management, Woodward said. Some of the spots will need to be retreated with herbicide for several additional years after the trees have been removed.

The trees are so hardy that it is not enough to cut them down. Woodward said that to prevent the continued spread of infestation, the stumps need to be sprayed immediately with herbicide. 

Hillberry said the retreating is simply a form of maintenance for him now that all the invasives have been removed from his land.

Still more needs to be done, he said and recalled a recent incident. “On the west side of the Big Horn River is a sportsmen’s easement. It is so congested with Russian olives that you couldn’t get to the easement. A fellow came by with a fly rod. I said, ‘This is private property.’ He said there was an easement somewhere nearby. I told him it was on other side of the river. He looked at the Russian olives and said, “I can’t get over there!”

“There are still some hold-outs. They say, ‘I like my privacy.’ You can take out the Russian olives, plant native species and still have your privacy,” Hillberry said. “Removal of the invasives changes the whole complexion of the river."