Depending on what time of year you look for this one, you may need special equipment to get to this location. During the hot summer months, you may be able to walk right up to it. During the winter and spring, you may need some sort of watercraft. Today, all i needed was a good pair of hip-waders.
Although there are probably many ways to get there, the way i went involved a two-mile roundtrip hike. Some of the trek involved a muddy well-used trail, and some of it involved some light bushwacking or following a game trail. Depending on river levels, some routes to this cache may be inaccessible. If you do decide to walk, wear a long-sleeve shirt, long pants, gloves, and head covering if it's springtime.
The cache is a standard ammo can covered in bark. Watch out for poison ivy, mad beavers, drunk deer, the dam-spilling-whim of the BPA, and the ghost of a certain geocacher.
NOTE: On January 18, the channel was about four feet deep--taller than hip waders, but okay for a kayak or chest-waders.
UPDATE: As of June 10, this cache is NOT accessible on foot. The entire channel was flooded today--probably about 15 feet deep. Also, the trail has become severely overgrown with nettles, blackberries, and other such fun plants. I can't recommend this cache to anyone until the water recedes, or if you have a boat that you can carry out there. I think the nearest launch point is rooster rock state park to the east and chinook landing to the west. I'm going to keep trying to check on this one to make sure it has survived the winter. If you're the first to beat me there, i've got a $25 gift certificate with your name on it.