Where do people drift to from the highway on Willow Creek?
if you float downstream from the highway, you'll arrive at the mouth of Willow at the Susitna River. There is a state park/campground there - which will become very popular as a king hotspot in a few weeks.
Coming from the highway bridge, you'll make a right turn onto a road that is marked with signs for: "Deshka Landing" & "Willow Creek State Recreation Area". I think it's the first right, headed south from the bridge, but if you pass the "3 River's Tackle Shop" shed, you missed it.