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Ranch research: University of Idaho personnel utilize Rinker Rock Creek Ranch for important science

by Wyoming Livestock Roundup

The Wood River Valley of central Idaho is home to a unique research and education facility affiliated with the University of Idaho. The university acquired this 10,400-acre ranch a few years ago for studies in rangeland management and conservation, while keeping it as a working cattle ranch.  

Today, most of the cattle on the Rinker Rock Creek Ranch are owned by the university, with extra cattle supplied by neighbors if a greater number are needed for a certain research project. 

Ranch background and personnel

Dr. John Hall, Extension beef specialist at the University of Idaho and superintendent of the Nancy M. Cummings Research, Extension and Education Center in Salmon, Idaho is involved with several of the research projects. In fact, the Nancy M. Cummings Center supplies most of the cattle for the Rinker Rock Creek Ranch.

Wyatt Prescott is the ranch manager, and his company Prescott Cattle and Consulting, has contracted with the university to manage the day-to-day cattle operations and facilitate management of the cattle. Prescott supplies crews and equipment for building and maintaining fences, water developments, handling the cattle, etc.

The Rinker family originally owned the ranch. However, they didn’t want it developed after they sold it so they worked with the Wood River Land Trust, Nature Conservancy and Natural Resource Conservation Service (NRCS) to get a grazing lands conservation easement on the private ground to keep it intact as a working ranch. The public land grazing of 11,000 acres is still tied to the ranch.

“At one point the Idaho Fish and Game Department was going to participate, but it didn’t happen. So the university, which had already been doing research on the ranch since 2016, acquired the property from the Wood River Land Trust and Nature Conservancy,” Hall explains.

Sage grouse research project

Dr. Melinda Ellison and Dr. Tracey Johnson have been conducting a study where cattle graze the wet meadows on the Rinker Rock Creek Ranch at different intensities during summer months, and they are looking at how the resources important to sage grouse for rearing chicks respond. 

In 2016, at the beginning of their study, the wet meadows were a monoculture with only a few grass species – meadow foxtail and some sedges. There wasn’t a lot of plant diversity, and there were not many plants sage grouse utilize in their diet when they raise chicks.  

One goal for this grazing management study was to figure out which level of grazing intensity may create better diversity and habitat for sage grouse.

Johnson, director of research at the Rinker Rock Creek Ranch and professor of wildlife habitat ecology in rangeland systems at the University of Idaho, says sage grouse in this area use some of the ranch meadows as breeding sites. 

“We are interested in understanding how best to manage livestock in a way that will accommodate both livestock and sage grouse,” she says.

“This ranch is a perfect place to do this work. Wet meadows are important to sage grouse, especially from mid to late summer. They use those areas for feeding their broods of chicks after the uplands dry out. The wet meadows, springs and riparian areas are crucial for many species,” says Johnson.

There are many ways to manipulate livestock grazing to achieve certain objectives. 

 “We can look at grazing utilization, grazing intensity, etc. and determine the response from the plant community to different levels of grazing. We were interested in how grazing utilization affects the forbs, such as broad leaf plants, sage grouse eat in the summer,” says Johnson.  

Cattlemen often monitor grass and how it responds but may not look at some of the other plants.

“Cattle eat mostly grass, but they also eat some forbs. The early project took place in 2017 and 2018, and we are currently working on a follow-up project. The early project was focused on understanding how the preferred forbs of sage grouse respond to grazing utilization,” Johnson explains. 

“We set up experimental pastures. There were some that were not grazed by cattle at all to serve as a control and some that were grazed moderately, with a target utilization of about 50 percent,” she continues. “We also had some pastures that were grazed heavily, with a target utilization of about 70 percent.”

Before the start of grazing season the researchers sampled the plant community in each pasture to see how abundant preferred forbs were.  

“We went back after taking the cattle out and sampled again. We were also interested in recovery time. If those areas were allowed to regrow and not be re-grazed in a year, what would their response be? We allowed eight weeks for regrowth and went back to sample again at the end of the season,” she says.

There were some interesting patterns in forage responses.  

“In terms of forbs sage grouse eat, we discovered in plant communities with a history of a lot of haying and grazing, dominated by forage grasses like meadow foxtail and smooth brome, there are not very many forbs.  It’s mostly grass,” says Johnson.

These areas had been rested from grazing for two years before the study began.

“They were rank and tall, but the cows did a good job of cleaning it up. In some of these areas there was so much old grass matted down, there was no place for forbs to grow,” Johnson says. “The first year of the study we saw a positive response from the perennial forbs sage grouse eat. The heavier the grazing, the more perennial forbs we found.”  

Other Rinker Rock Creek research projects

In another project, Ellison is looking at the impact of cattle on willows in riparian areas and how much they browse on those willows, compared with the impact of moose, elk, deer or other browsers.

Dr. Tim Prather, a weed specialist, is looking at ways to determine the areas of highest risk, and how to better target weed management efforts.  

One of the projects Hall is involved in is comparing a cow/calf management system, which utilizes rangeland with an irrigated pasture system at the Nancy M. Cummings Center. Half of the herd goes to Rock Creek in the summer and the other half stays on irrigated pasture. 

 “Then, all the cattle are here at the Nancy M. Cummings Center from December through early May for winter feeding, calving and the early part of breeding season,” says Hall.

“We’re comparing these two groups, looking at animal performance, economics, fetal programming and comparing the effects of the two environments on the fetuses to see if the environment has a lifelong impact on the particular animal,” he continues. “Each system has some deficiencies, and we hope to find management options that producers could use to improve those.”

Dr. Jim Sprinkle conducts feed-efficiency testing on all of the heifers and looks at how the heifers utilize the range later as cows to see if feed-efficient heifers use range differently than heifers that are not as feed-efficient. Sprinkle uses GPS collars on some cattle to gather this information.

“We continue to get more projects all the time,” says Hall. “This ranch and range provides opportunity to study many things that are important to cattle producers in this kind of environment.”

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Heather Smith Thomas is a corresponding writer for the Wyoming Livestock Roundup. Send comments on this article to

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