A Decade of Bayer’s indaziflam Experiments & Glyphosate in Boulder County N. Foothills of Conservation Area–prior to BLM’s 2024 EIS.
Nearly a decade before the Bureau of Land Management finalized its 2024 indaziflam herbicide environmental impact statement, in 2016 Boulder County Parks & Open Space & Parks (BCPOS) had already begun using indaziflam (marketed as Rejuvra in 2020/Esplanade used 2016-2020) manufactured by Bayer Crop Science/a.k.a. Envu)across the North Foothills Conservation Area.
These applications occurred on lands considered globally significant ecological habitat and Indigenous ceremonial landscapes– The Denver Botanical Garden table feeding the recent Restoration Ecology analysis and shows that 9 of 12 indaziflam study sites (@ Rabbit Mountain, Hall Ranch, Heil Ranch) later burned in 2020 or 2024–and in a March 3-4, 2026 wildfire that burned 7.6 acres at Heil Ranch within the 2020 Cal-wood scar burn “CBS Colorado: Describes the wildfire in Heil Valley Ranch occured “in an area where there is already a burn scar from a previous wildfire.” County records show petrochemical herbicides including indaziflam applications on October-December 2025 used again at Heil Ranch, just months before this wildfire.
Ron Stewart Preserve
South Down / Indian Mountain
Heil Valley Ranch
Hall Ranch
CORA and public records evidences that for over a decade indaziflam and glyphosate were applied via helicopter boom spraying, drones, and tractor on these foothill conservation area.
To put this into perspective:
Even today (2026), BLM field offices in states like Wyoming must conduct site-specific NEPA reviews before spraying Rejuvraeven after BLM’s Environmental Impact Study (EIS 2025).
These additional EIS reviews apply to 18 million acres of federal land.
No comparable environmental review was conducted prior, during or post Boulder County’s decade of its admitted “research & testing” using tractorand aerial applications on Conservation Lands (BCPOS’ CORA documents) including riparian habitat and wildlife preserve (@Ron Stewart Preserve).
The North Foothills Conservation Area was also sprayed with indaziflam for expressed but counterintuitive intent of “wildfire mitigation” (CORA and public records expose).
CALL TO ACTION
Call to Action
1. Ask Boulder County to Extend the Moratorium
With drone spraying temporarily paused, now is the moment to request greater transparency and accountability.
We are urging residents to contact the Boulder County Commissioners and request:
An extension of the moratorium on aerial herbicide spraying and indaziflam use through at least 2026
An environmental impact study by an independent source, accessing past and proposed herbicide use on all sites used in BCPOS’ research & testing–that made BCPOS’ Weed Manager Joe Swanson made Boulder County Ground Zero for the research & testing of Bayer’s Indaziflam
Meaningful consultation with Indigenous communities and regenerative farmers
Email: commissioners@bouldercounty.gov
Call: 303-441-3500
Public comments logged now can influence the County’s next decision.
Hunter Luvins’ Call to Action to the Boulder Counter Commissioner’s @ Townhall 2026 “Stop poisoning Us…what you’re doing is deliberately allowing a corrupt process to poison us... I run an organic operation– when you spray–you will be destroying what I’ve been building up–what my neighbors have been building up. You have the power to do that–hold another hearing, reopen the procedure but…stop poisoning us”.
2. Support the Getting BoCo Out of the Weeds Campaign
Since launching in late 2022, the campaign has already achieved several major policy shifts:
Key wins include:
Informing the Boulder County Commissioners that their staff @BCPOS was using aerial herbicide applications in the N. Foothills Conservation Area. Commissioners Marta Loachiam and Commissioner Levy each stated that they were “unaware” and “shocked” that this method was used as a weed management tool in Boulder County.
Triggering a two-year review of Boulder County’s 2004 Integrated Weed Management Plan, which had gone 16 years without review despite Colorado Department of Agriculture requirements (2023-24)
2004 Integrated Weed Management Plan (IWMP) did not approve aerial applications for weed management. Neither does the 2024 IWMP.
Securing exclusion of Dicamba and 2,4-D from open space use
2023 procured moratorium on helicopter spraying of herbicides
Achieving new restrictions on glyphosate use on open space
Halting a three-day helicopter (indaziflam) herbicide spray operation scheduled for October 3–5, 2025 on federal land
Stopping Red Hill drone spraying of indaziflam in 2026
Initiating an active investigation by the Colorado Department of Agriculture (CDA) into BCPOS herbicide testing, research and operational experience on open space lands 2016-2025.
There is still more work to be done to Get BoCo Out of the Weeds–Banning aerial drone applications, procuring environmental impact studies on all sites BCPOS used for operational experience of indaziflam in the N. Foothills Conservation Area.
Your support makes our research and environmental advocacy–required to protect the St Vrain Valley’s globally significant ecosystem– possible. Our work protects our local communities and indigenous friends from unchecked chemical exposure; ensures local management’s compliance with federal and state regulations and guardrails; and advocacy against industrial agricultural practices on open space public lands.
