Community Agriculture Alliance: Leafy spurge is bad news

University of Wyoming sheep are helping with research to develop management strategies for leafy spurge.
Peter A. Williams/courtesy

June is the best time of year to see just how much territory invasive leafy spurge has taken away from us. Take a drive on U.S. Highway 40 west of Hayden and scan the Yampa River floodplain for a shockingly bright yellow-green color. That’s leafy spurge.

We all need to be concerned about this accidental Eurasian introduction. It pushes out native vegetation, is poisonous to cattle and horses, contaminates hay crops and pasture land, compromises habitat value for elk and other wildlife, is difficult to manage and, ultimately, costs money. 

Worst of all, it is moving in the water — traveling downstream and establishing along the river, lining irrigation ditch banks and spreading into irrigated hay and pasture land.

After the 2011 high-water year on the Yampa River, it popped up in hundreds of new patches on public lands in Little Yampa Canyon and Dinosaur National Monument. It has reached the confluence of the Yampa and Green rivers and is now moving down the Green River in Utah.

The cost to agriculture is staggering. Millions of acres are affected in 29 states. Leafy spurge is listed among the top 25 invasive terrestrial weed species in a 2018 report by the Western Governors Association.

In 2015, concerned residents and partner agencies and organizations began meeting and working together to find ways of keeping leafy spurge from expanding to new areas in the Yampa Valley and help land owners to combat this aggressive weed. This group calls itself the Yampa River Leafy Spurge Project.

“We are just an informal group of folks who want to find solutions to a problem that threatens the place we live in, care about and make a living from,” said Ben Beall, a local resident and former Routt County commissioner.

The Yampa River Leafy Spurge Project seeks grants to support education and outreach programs, spurge mapping, treatment and scientific research. This year, a Yampa-White-Green Basin Roundtable grant is supporting two research projects with the University of Wyoming and development of a biological control program that will provide opportunities for engaging youth and local volunteers.

Leafy spurge spreading along the Maybell ditch in Moffat County.
Peter A. Williams/courtesy

Tamara Naumann, a Moffat County resident and project volunteer, explains that “we hope to develop effective and sustainable management programs specific to the Yampa River Basin by supporting needed scientific work, engaging local youth and building on local knowledge and relationships as we strive to protect both agricultural and environmental land and water uses for our future.”

For more information or to donate or volunteer, visit

Tamara Naumann is with the Yampa River Leafy Spurge Project. Contact Naumann at 970-620-0182 or

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