The Bureau of Indian Affairs Navajo Regional Office released the Record of Decision (ROD) for the Navajo Nation Integrated Weed Management Plan to control noxious weeds across the Navajo Nation on December 12, 2022.


The ROD official selects the full Navajo Nation Integrated Weed Management to control, manage, and eradicated noxious weeds on the Navajo Nation through an integrated approach that combines mechanical, manual, biological, chemical, and cultural control methods to improve their effectiveness. 

This project started in 2012, with the Notice of Intent (NOI) published in the Federal Register on January 14, 2013 and Public Scoping completed on March 20, 2013, with an extended 30-day comment period starting on April 29, 2021.  Public Review of the Draft PEIS was done from October 29, 2021 to December 15, 2021. The Final PEIS was released on September 2, 2022 for public review. 

The Final PEIS is available to the public along with the Record of Decision and the Final Navajo Nation Integrated Weed Management Plan. 

A BIA employee records GPS data in front of a dense cluster of musk thistle near Shonto Wash in Arizona.

Figure 1. BIA Natural Resources staff mapping an infestation of Scotch thistle inside Shonto Wash. 

Purpose and Need

Noxious weeds are non-native plants that displace, reduce, and eliminate native plants and animals from their habitats after their introduction. On the Navajo Nation, noxious weed inventories have documented close to 80,000 acres of infestations. These plants pose a serious threat to the biological diversity, livestock production, wildlife habitat, and the ecological health of the region. The BIA, in partnership with the project’s cooperating agencies, has developed an integrated weed management plan to address the detrimental impacts of noxious weed on tribal trust and allotment lands (see map below). An integrated weed management plan combines several recommended techniques and approaches for managing and controlling noxious weeds to provide the greatest level of control. 

Mitigation measures were developed with Navajo Nation Environmental Protection Agency, Navajo Nation Department of Fish and Wildlife, and U.S. Fish and Wildlife Service to protect air and water quality and listed and sensitive wildlife and plant species during weed treatments. The project has completed an informal Section 7 consultation process with the U.S. Fish and Wildlife Service and the Navajo Nation Department of Fish and Wildlife to address concerns for federally and tribally listed species. Using an integrated approach allows managers to adjust weed treatment options based on community concerns, project location, weed species present, and avoidance or protection measures to prevent impacts to valuable resources while providing effective control. 

Map of the Navajo Nation lands administered by the Bureau of Indian Affairs. The Navajo Nation is divided by Agency, with Western Agency in gray, Shiprock Agency in tan, Eastern Agency in blue, Chinle Agency in bright yellow, Fort Defiance Agency in red, Navajo Partitioned Lands in green, and New Lands in magenta.

The project area for the Navajo Nation Integrated Weed Management Plan. 

The methods of noxious weed control considered in the integrated weed management plan include manual, mechanical, cultural, biological, and herbicide or chemical treatments. The BIA identified the following resources to evaluate the effects of the proposed action: paleontological resources; soils, water, and air, vegetation, wildlife, agriculture, public health, socioeconomics, cultural resources, environmental justice, and areas with special designation.