The Colorado Noxious Weed Act (§ 35-5.5-101, C.R.S. (2009), et seq.):

• States that certain invasive weeds pose a threat to the continued economic and environmental value of the land in Colorado;
• Designates these weeds as "noxious" in Colorado;
• Mandates their management by all landowners in the state. 

Enforce its Term

The act contains specific provisions empowering the county to enforce its terms (including without limitation §§ 35-5.5-108.5, -109, and -110).  The Pitkin County Land manager, Code Enforcement Officer, and Sheriff, and their respective designees, have been designated by the county as "authorized agents" for this purpose.