I don't want to throw cold water on your trip but the Kalama River has very low water levels right now. If you take a drift boat, I would stay in the reach between Pritchard's and Modrow Bridge (remember the section between Hatchery Creek and the gas pipeline behind Kalama River Bait and Tackle is flies only!). Even then, be prepared to get out occasionally and pull your boat through the riffles. They're too shallow to float a drift boat even without any weight. It's likely to stay low until we get rain. Which isn't in the forecast before Saturday.

The coho will be stacked up in the large pools. Wiggle warts will work as suggested. My recommendation is to use #4 spinners in orange or chartruese. Work them very SLOWLY along the bottom. Consider drifting eggs too. Big gobs of eggs early in the morning seem to work. Good luck.