Emerald Ash Borer

To slow the spread of EAB, The Oregon Department of Agriculture issued a permanent quarantine across Multnomah, Washington, Yamhill, Marion and Clackamas Counties. Tree materials from ash, olive, and white fringe tree, must remain within quarantined counties. 

For more information, visit the Oregon Department of Agriculture.

Emerald ash borer (EAB) is an invasive wood-boring beetle. EAB is responsible for the death and decline of millions of ash trees in North America. It was first detected in the Midwest and east coast in 2002.

In June, 2022, EAB was observed on the west coast. The first sighting was in Forest Grove, Oregon. In September 2025, EAB was confirmed in East Portland, a few miles from Gresham.

All ash species (Fraxinus spp.) are at risk from EAB, including the native Oregon ash (Fraxinus latifolia). This tree species is a vital part of natural areas along rivers and streams in Western Oregon. EAB changes habitats as it kills Oregon ash trees.

Non-native ash species planted as street and landscape trees are also at risk. EAB will damage ash trees in Gresham neighborhoods.

• Emeral Ash Borer in Oregon
• Oregon State University - EAB identification 
• Oregon Department of Agriculture, EAB project
• Oregon Department of Agriculture, EAB Oregon look-alikes
• Oregon Department of Agriculture, EAB quarantine alert
• Oregon State University - Identifying ash trees in Oregon
• Oregon response plan
• Oregon invasive species hotline
• Oregon Department of Forestry fact sheet