Report your otter sightings to our Rivers of Western Washington research project.


Action Alert: Submit your Sightings

River otters are found in water systems all over Washington state and we need your help to spot them! If you observe a river otter, please report your sightings to help us capture data on otter range and behavior.




Otter Spotter Tips and Etiquette

  • Respect all posted signs and property lines when otter spotting.

  • If you spot an otter, please observe from a safe distance. Do not approach or harass the otters.

  • Take only photos and notes, never resources or materials from the area of your sighting.

  • Be aware of your surroundings and stay safe, especially when navigating waterways or areas with low visibility.

  • Be prepared with helpful gear including binoculars, camera and/or notebook and pen for recording observations, and GPS detector or app.

  • Not sure if you've seen a river otter or a sea otter? Use these helpful tips from Seattle Aquarium to tell them apart.

  • River otters can be confused for several other local wildlife species. Check out our semi-aquatic mammal guide to help with your identification skills.


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Sentinels of Ecological Health: About the Research Project

The Green River flows from undeveloped Washington wildland through increasingly urbanized areas to become the Duwamish River—Seattle’s major industrial corridor since the early 1900s. Along the entire 65+ mile route, one mammal that calls the river home can serve as a telling indicator of the health of this critical waterway—the North American river otter.

The Lower Duwamish Waterway (LDW)—the final 5 miles of the river as it empties into Puget Sound—has a complex history and challenging future. The US Environmental Protection Agency has identified the LDW as a Superfund site for environmental remediation in response to long-term industrial pollutant exposure and urgent concern about contaminant levels.

Studying the population trends of river otters and the toxins in their scat along the length of the Green-Duwamish River will establish a baseline understanding of the contaminant load under a range of conditions, including the current polluted state of the LDW. Such empirical data can help inform long-term studies and shape conservation strategies as remediation efforts continue at the Superfund site.

See the latest results