Cattle grazing – along with forest thinning and prescribed burning – has been an effective way to help manage and reduce invasive weeds south of the National Center for Atmospheric Research

The City of Boulder will work with local ranchers in May to return cattle on open space south of the National Center for Atmospheric Research (NCAR) to support healthy native plant communities and help reduce wildfire risks.

This year will mark the 11th year that City of Boulder Open Space and Mountain Parks (OSMP) staff has worked with local ranchers who lease open space agricultural land to conduct cattle grazing south of Boulder. Long-term monitoring of cattle grazing – which is the most cost-effective tool to manage vegetation in the rocky open space area – has shown it to be an effective way to reduce invasive weeds, such as tall oatgrass, that can fuel wildfires.

Observations have also indicated that the land management practice – when combined with fast actions from first responders and other city work to address wildfire risks, such as prescribed burning and forest thinning – helped slow the March 2022 NCAR Fire and kept it from becoming a more intense fire.

Cattle grazing south of Boulder aims to support ecosystems by removing tall oatgrass, a highly invasive, non-native weed species. It quickly forms dense spreading stands that prevent native vegetation from receiving essential light, moisture and nutrients. Its spread:

  • Threatens rare and uncommon native grassland plant communities, including globally imperiled tallgrass prairie.
  • Can impact a wide range of wildlife species – such as grassland birds, mule deer and wild turkey – that depend on OSMP’s more diverse native plant communities.
  • Creates additional fuel for wildfires, increasing fire risks for Boulder neighborhoods.

City of Boulder Open Space and Mountain Parks staff will rotate cattle through five different areas south of Boulder from Tuesday, May 6, through through the end of June. OSMP reminds open space visitors to be mindful of cattle when recreating south of Boulder. Cattle can be aggressive, particularly if there are calves present. Remember:

  • Do not approach cattle.
  • Do not damage/remove a gate.
  • Never get between a cow and her calf.
  • Leash dogs in areas where cattle are present.
  • Maintain a safe distance.
  • Always close gates behind you!

OSMP anticipates rotating cattle through these five pastures from May 6 through July 1. Wildfire resilience in the City of Boulder is a shared responsibility. This grazing effort is one of many projects the city is undertaking to help reduce wildfire risk. Learn how this work fits into broader wildfire resilience efforts at Boulder Wildfire Projects.

Map showing where cattle grazing will occur on Shanahan Ridge south of Boulder