Invasive Plants and Animals

Yellow starthistle flower


Many areas on the Wallowa-Whitman National Forest are under attack from dozens of invasive plants, animals, and pathogens. These exotic invaders disrupt the natural ecological balance, negatively impact the quality of our outdoor recreation experiences, decrease resources values, reduce access to these areas, and can threaten human health and safety. In addition the loss of outdoor recreation uses in an area due to invasive species infestations can also drastically impact local recreation-dependent economies.



What is an Invasive Species?

Invasive species have been characterized as a “catastrophic wildfire in slow motion.” Thousands of non-native invasive plants, insects, fish, mollusks, crustaceans, pathogens, mammals, birds, reptiles, and amphibians have infested hundreds of millions of acres of land and water across the Nation, causing massive disruptions in ecosystem function, reducing biodiversity, and degrading ecosystem health in our Nation’s forests, prairies, mountains, wetlands, rivers, and oceans. Invasive organisms affect the health of not only the Nation’s forests and rangelands but also of wildlife, livestock, fish, and humans.

A species is considered invasive if it meets these two criteria:

  • It is nonnative to the ecosystem under consideration, and
  • Its introduction causes or is likely to cause economic or environmental harm or harm to human health.

Information about invasive species threatening the National Forests is found at the Forest Service Invasive Species website.


To address these threats the Wallowa-Whitman National Forest and Pacific Northwest Region have developed these plans

2022 Invasive Plant Treatment Area Maps: Treatments occur over the course of the field season, typically from May to October.

North Zone Treatment Maps

South Zone Treatment Maps

How You Can Help

As a visitor, permit holder, contractor or adjacent landowner you can help reduce the spread and infestation of invasive species. By learning about how species are brought in or the spread across the Forest, visitors can be part of the solution to reduce. The following outdoor activities are being emphasized this year to reduced the introduction and spread of invasive species:



Regulations have been established to prevent or reduce the spread of invasive species on the Forest. Current regulations are: 

Other Websites

These websites offer additional information about invasive plants and animals.