Missoula County Weed District & Extension

Mission & History

Mission Statement: To inform and educate the residents of Missoula County about the problems associated with noxious weeds, to facilitate a process for all private and public landowners to minimize the impact of noxious weeds through the use of sound ecological practices, and to monitor the control and eradication of noxious weeds throughout Missoula County.

The role of the Missoula County Weed District is to:

  1. provide education and leadership that will enable land managers to manage their noxious weeds
  2. bring the landowners and land managers together to address noxious weeds on a community basis
  3. address weeds classified as new invaders before they develop into a major problem


An Historical Perspective
As farming became established in the Missoula Valley in the 1800's, farming practices such as soil disturbances and overgrazing created open niches in native plant communities. Noxious weeds seeds that were introduced in livestock feed and crop seed quickly took advantage of these empty niches. Once established, weeds spread along road rights-of-way and through irrigation canals, rivers and streams. In Missoula and other areas of the state, thistles were one of the first plants to become problematic.

In 1895, Montana passed the first noxious weed law, declaring Canada thistle, Russian thistle and Scotch thistle to be common nuisances.

In 1922, the Montana Legislature enacted the Montana County Noxious Weed Control Act, which gave county government the legal authority for noxious weed management programs.

Following World War II and the emergence of "modern" herbicides such as 2,4-D, Montana counties started organizing some of the programs that we have today. In Missoula County, spotted knapweed and leafy spurge infestations became epidemic in proportion which added pressure for more to be done to control noxious weeds.

From the 1950's to 1985, the Missoula County Weed District conducted noxious weed control programs which consisted primarily of spraying herbicides. The state contracted with Missoula County Weed District to treat road rights-of-way. The Missoula County Weed District also contracted with local landowners to treat noxious weeds.


balsam hillIn 1974, the Missoula County Weed District partnered with other western Montana agencies interested in developing a biological weed control program for spotted knapweed. Other noxious weeds like leafy spurge, houndstongue, sulfur cinquefoil and hawkweed were later added to the list for the development of a biological agent.

In 1985, the Missoula County Commissioners discontinued the herbicide program due to concerns over the loss of liability insurance, lack of integrated weed management (link to IWM page) practices and the lack of landowner involvement and commitment.

In 2000, the Missoula voters approved 2 mills for the Noxious Weed Control Program. The Weed Board responded to the renewed public support for noxious weed management in Missoula County. They recognized the need to implement a plan to address the widespread noxious weed infestations by increasing landowner, land manager and public involvement in weed management.