Links updated on 02/01/2014
"Fishing has been decent at Lake Stevens for kokanee in the 10- to 11-inch size range. American Lake is also quite good for kokanee with some up to 16 inches."
Other good kokanee lakes are Roesiger, Samish, Cavanaugh, Keechelus and Kachess, Riffle and Clear lake up by Eatonville.
Links
Articles on Kokanee Fishing
Kokanee Power (California)