Jefferson County Open Space in collaboration with other land management agencies (Larimer County’s Department of Natural Resources, City of Fort Collins Natural Areas Department, Colorado Parks & Wildlife, and Boulder County Parks and Open Space) were awarded grant funding from the National Fish and Wildlife Foundation to implement a landscape-scale restoration project aimed at restoring critical winter range habitat for mule deer and elk populations by controlling and eradicating non-native annual grasses across more than 4,300 acres along Colorado’s Front Range. The goals of the project are to eliminate annual invasive grasses from the treatment areas, increase the cover and diversity of native species, and enhance critical food resources for mule deer and elk.

For this trip, attendees will visit Matthews/Winters Park to learn about the collaboration, implementation, and monitoring of the project.

What to Expect: Attendees will meet at the Matthews/Winters Park Trailhead in Morrison, CO and hike approximately 3.5 miles along a moderate intensity trail to view the two different treatments. The weather can be unpredictable this time of year, so long pants, sturdy closed-toed footwear, sun-protective clothing (e.g. wide-brimmed hat, sunglasses, etc.) are recommended. Rattlesnakes have been observed throughout the project area so attendees should be prepared for possible encounters during the hike.

Detailed Description

Invasive winter annuals, such as cheatgrass and feral rye, are the second largest threat to native ecosystems, surpassed only by land conversion. To bolster native grassland restoration efforts along the Colorado Front Range, Jefferson County Open Space partnered with Larimer County’s Department of Natural Resources, City of Fort Collins Natural Areas Department, Boulder County Parks and Open Space, and Colorado Parks and Wildlife to develop a landscape-level approach to managing invasive annuals with the herbicide indaziflam. Native plant communities treated with a single application of indaziflam have demonstrated significant improvement within the first growing season.

This restoration project is a 700-acre project and is one piece of a larger multi-agency collaboration that aims to restore more than 4,300 acres of grassland and shrubland habitat that has been negatively impacted by annual invasive grasses and forbs. The goals of the project are to eliminate annual invasive grasses from the treatment areas, increase the cover and diversity of native species, and enhance critical food resources for mule deer and elk.

Implementation involved two aerial herbicide applications using the herbicides indaziflam and imazapic (trade names Rejuvra and Plateau, respectively), conducted in 2022 and 2024. Each application treated approximately 350 acres, covering the entire 700-acre project area. Pretreatment monitoring began in summer 2022, with intercept cover assessments conducted along four transects in treated areas and one in an untreated area. These assessments measured species cover, frequency, richness, floristic quality, and diversity indices. Monitoring efforts will continue through 2026 to evaluate the long term success of the project.