Protecting High Quality Rangelands in Garfield County from Invasive Weed Spread

2006 Annual Report for FW05-301

Project Type: Professional + Producer
Funds awarded in 2005: $20,000.00
Projected End Date: 12/31/2008
Region: Western
State: Montana
Principal Investigator:
Eric Miller
Montana State University

Protecting High Quality Rangelands in Garfield County from Invasive Weed Spread


Weed-free rangelands are an ecological and economic benefit to everyone who utilizes rangelands. They provide decreased cost of production and increased carrying capacity for livestock producers, native habitat for wildlife and native plant and grass species for recreationalists. Garfield County Montana is comprised of 70% rangeland used primarily for livestock production, and the vast majority of it is free of noxious weeds. County landowners are intent on maintaining the rangelands in their current state without any noxious weeds!

Widespread noxious weed infestations have not historically been a problem in Garfield County due to the county’s remoteness and lack of bisecting waterways. Over the past 10 years, noxious weed occurrences have increased in the county as they have in much of Montana. The increased occurrences can be attributed to: increased vehicle traffic on the bisecting highways, increased hunter activity on secondary roads and private roads, and increased reliance on out-of-county hay. The general increase in noxious weeds across the state and the lack of interest or recognition of their impacts by the general population seems to have increased the transportation of noxious weed seeds from areas of high noxious weed densities to Garfield County.

In an effort to maintain the current low or non-existent noxious weed levels in Garfield County, the Weed Prevention Area (WPA) concept was developed. Large contiguous acreages have been included in the WPA with many of the landowners working jointly to scout for new weed threats. The principle behind the concept is to limit new infestations by increasing private landowners, hunters and other visitors’ awareness of the detrimental impacts of noxious weeds to the environment. In addition to the awareness message, landowners are encouraged to routinely monitor their private and leased lands for new weed infestations and work aggressively to eradicate any noxious weeds they located. To assist the landowners in tracking the weed-free status of their lands, GPS technologies have been employed to map current weed locations and to verify locations and acreages of non-infested lands.

Objectives/Performance Targets

  • The primary objectives of the WPA project in 2006 were to:

    Provide weed prevention information to the landowners/managers
    Promote an awareness campaign
    Establish a baseline number of acres of weed- infested lands within the WPA
    Develop baseline maps of the area
    Control infestations along egress routes to the WPA
    Provide means to control new local weed infestations
    Provide the means for landowner to monitor their land for new weed intrusions


In 2006 WPA participants received and reviewed the goals and strategies of the Garfield County WPA. They received WPA brochures for their own use and disseminated the brochures to recreational land users. Signs delineating the WPA have been posted at primary ingress locations and on access roads to the primary ranch buildings. Approximately 60,000 acres of rangeland were monitored for noxious weeds to develop maps and a baseline value of noxious weeds within the area. A small infestation of Russian knapweed and scattered salt cedar were detected and controlled along the boundary of the WPA.

New protocols were developed for monitoring noxious weeds while the mapping efforts were being conducted in 2006. The original concept was to visually inspect the vast majority of land and record the inspected areas with GPS tracking systems. While in theory the concept was good, practically it was impossible to accomplish.

Research has shown that most new weed infestations originate along high use areas and waterways, easy seed transmittal locations. The new procedure calls for identifying all moderate to high use roads, or those used by hunters in the fall, on the ranch and all the major coulees and actively flowing waterways. Efforts are then concentrated to the higher probability areas, and they are the locations targeted by a hired weed scout.

The weed scout’s job is to visually inspect each area and record progress with a hand held GPS unit. The data are later downloaded and transferred to mapping software where ranch and WPA maps are made identifying inspected areas and the locations of known weed infestations.

The weed scout visually inspected the high probability weed locations and any adjoining drainages. The weed scout used a 4 wheeler to cover the area and carried a mobile GPS unit to record the entire route covered. Any location that had a listed noxious weed was recorded as a unique point with the weed identified in the GPS. The data were later downloaded and maps have been created to show the areas that were monitored. The data will be analyzed to determine the extent of weed infestations and, over several years, monitor and evaluate weed trends.

Data recorded will be used as a baseline for the WPA of weed presence and will be used to help determine if more weeds are entering the area over the years. The goal is to show long-term trends in weed spread or the lack thereof, providing proof to the effectiveness of Weed Prevention Areas. Participating ranches have received GPS units for employees or owners to carry and mark any new weed infestation they come across in their daily ranch activities.

Impacts and Contributions/Outcomes

The baseline maps are a very important component of the project. They represent a means to measure the long-term effectiveness of weed prevention and will provide documentations of weed locations.

Signs are being made for all the participants. The signs will be posted along entry routes or roads to each ranch. The signs indicate the ranch is part of the WPA and assist in raising weed awareness.

Availability of manageable sized spray units has been a concern of many landowners within the WPA. Two commercial grade 4-wheeler units have been ordered and will be centrally located in the WPA for use by all the participants. The units will be used to control new infestations as they are located and will decrease the response time to control new weed infestations.


Robert Cosgriff

Jordan, MT
Office Phone: 4065576108
Colin Murnion

Jordan, MT
Office Phone: 4065572454
Pohney Murnion

Jordan, MT
Office Phone: 4068531374