The Carbon dumps into the Puyallup just downstream of Orting, right about McMillan area. Check it out on a map.

There's a couple of access points right along that road; just look for all the pickups and cars parked along the road.

You use the same gear and technique as in the Puyallup. I've usually done better after the weather cools down some and the water clears. However, it sounds like guys are nailing them down there now. The rain will bring a bunch in.