Invasive Plants Project
Combating noxious weeds threatening the Upper Missouri watershed
Why Should We Care About Weeds?
The Upper Missouri River watershed faces serious threats from noxious weeds. Users between Holter Dam and Cascade encounter Knapweed, Toadflax, Leafy Spurge, Houndstongue, Hoary Alyssum, and Purple Loosestrife at fishing access sites, riverbanks, and islands. These invasive species displace native vegetation and undermine the ecological health of the entire watershed.
Ecological Threats
- Degrade water quality by displacing native plants that stabilize soil and filter runoff
- Reduce native biological diversity across the watershed
- Negatively impact elk, deer, bighorn sheep, swans, and ducks
- Spotted Knapweed: increased water runoff by 56% and soil erosion by 192%
- Dalmatian Toadflax: increased 322% in just four years
- Dense Knapweed: decreased winter elk forage by 50-90%
- Purple Loosestrife: replaces desirable food plants, negatively affecting aquatic mammals
Noxious Weeds in the Watershed
Hoary Alyssum
Leafy Spurge
Purple Loosestrife
Spotted Knapweed
Yellow Toadflax
Weed Pulling in Action
UMOWA board members and volunteers regularly head to the riverbanks to hand-pull noxious weeds before they can seed and spread. A single afternoon of work can fill a truck bed with bagged invasives — keeping them out of the watershed and away from native plant communities.
Every volunteer hour translates into fewer weeds next season and healthier ground along the Upper Missouri.
Help Fund This Important Project
Your donation supports the fight against invasive species in the Upper Missouri watershed.