Multnomah channel boat launch on Sauvie Island

There's a little boat launch on Sauvie Island off NW Ferry Rd. Do any of you know if it's part of the wildlife area? I wonder if I need to pay $10 to park there and launch my kayak. The maps and info online aren't really helping me out
I went and checked this out last weekend. It is a free launch but gets wicked busy on a Saturday afternoon. I like to get out early so it wasn't an issue launching or parking.