List A species are invasive weeds that are either not known to occur in Colorado or are of very limited distribution and are required to be eradicated.
List B species are invasive weeds with populations of varying distribution and densities within the state. The level of mandated control is based on local conditions. These weeds may require eradication within certain areas of the state.
List C species are widespread and common within the state. They may pose a risk to agricultural lands and may be required to be controlled