100 Worst List

WORKING TOGETHER TO KEEP THESE 100 WORST INVADERS OUT
Keeping them out of our state (or limiting their expansion if they’re already here) is a priority that protects our clean water, wildlife habitat, working landscapes and the unique beauty of our state forfuture generations.

ABOUT THE 100 WORST LIST
Thousands of invaders could qualify for listing. To be added to Oregon’s 100 Worst list of invasive species, the invader must be:

  • non-native to Oregon
  • absent from the state or limited to a small
  • contained range within the state
  • a greater threat than something already listed

IN CREATING THIS LIST, THE OREGON INVASIVE SPECIES COUNCIL WEIGHS FACTORS SUCH AS:

  • the risk to human health
  • the impact of the species in habitats similarto those found in Oregon
  • the likeliness of the species to cause significant economic loss
  • the difficulty otherregions have had eradicating the invader
  • the capacity forthe species to spread in Oregon

To view/download the History of Edits to the 100 Worst, click here.