There are many ways to plunk for salmon and steelhead on Oregon rivers, but here's the most basic setup
I'd edit this a bit from when I made it last spring, but the dropper length can be anywhere from 0-12 inches. Rarely more than that. The Spinglo should be in the 2-4 size, with size 1 hooks (sockeye) and upto 5/0 for big chinook.
edit: here's more info i just put together