Mid-October marks the peak of chum salmon (Oncorhynchus keta) runs throughout Pacific Northwest rivers and streams, representing the final major salmon spawning event of the year. Chum salmon, also called "dog salmon" for their prominent canine-like teeth that males develop during spawning, enter coastal streams in massive numbers from October through January. These fish typically weigh 8-15 pounds and develop distinctive vertical bars of red, purple, and green during spawning, creating striking colors against autumn backgrounds. Chum salmon are unique in spawning primarily in the lower reaches of rivers and in very small coastal streams, making them accessible to observers. Their late timing and preference for small streams means chum often spawn in urban and suburban waterways, providing remarkable wildlife viewing opportunities. Chum runs represent autumn's culmination, with thousands of fish crowding small creeks before the final transition to winter.

Willamette Valley hazelnuts are in full harvest—freshly shelled Oregon filberts are available at Portland-area farmers markets and specialty grocers, and the state's hazelnut harvest is one of the most distinctly regional agricultural events of fall. The largest seasonal chanterelle hauls typically happen after October rains following a dry spell. Chum salmon continue running throughout the lower Columbia and coastal tributaries.