Its the late-season on the Yakima, and those anglers who are willing to dress warm and adjust their tactics are finding plenty of fish and solitude.
Nymphing has been producing fish in good numbers with a #8-10 rubberlegs trailed by a firebead PT or Hare's Ear in #16-18 under a Thingamabobber. The fish are definitely in the slower, deeper pools, so focus on the stuff that is slower than walking speed, with 4-6' of depth. Fishing in the middle of the day is going to be best, with the colder temps keeping the fish fairly inactive early and late.
Streamer fishing has also been productive, although the fish are not moving for a retrieved fly like they were a few weeks ago. Smaller patterns on a slow-strip or swing should get some love, with more natural colors like brown, olive and black. The Sculpzilla is a guide favorite, and fishes well both on a streamertip from the boat, as well as on the swing.
The crowds are gone, and the fishing is still going strong on the Yakima River. Although you may not see big numbers of fish this time of year, we generally see some of our biggest fish caught during the winter months. A pretty good tradeoff in our opinion!