Portland is a very unique city for fishing. With the Columbia River, Willamette River, Sandy River and Clackamas River, there is no shortage of fishing opportunities. Columbia River Spring Chinook: March - May. Willamette River Spring Chinook: April - June. Columbia River Fall Salmon: September - October. Winter Steelhead on the Sandy and Clackamas Rivers: February - March. Catch and Release Sturgeon on the Willamette River or Columbia River: November - May.