Kid Cowlitz here. Depending on what direction you are coming from, take exit #68 off of I-5. Go past Spiffy's restaurant, it'll be on your right if you are going the right way. This will be HWY 12.

Keep going and going, the road will be a 3 lane road going up a hill (I think?) As you go down the hill, you will see the big town of Salkum. Please do not blink, whatever you do or otherwise you'll drive on by.

Take your immediate right. There should be a sign stating SALMON HATCHERY. Brown sign with white letters. After you turn, you'll see the Barrier Dam Campground on your left and then a dead-end. Turn left at the dead-end and then veer right. All the way down at the end of the parking lot are 2 launches.

You can also put in at the Blue Creek launch. This will put you above the creek and Massey's bar. Follow the same directions above, except the TROUT HATCHERY sign is well before the salmon hatchery sign. There is another launch or two below these I think. I suggest getting or looking in a gazeteer. The Cowlitz has a shuttle service, but I don't know the number. You may can stop and ask the folks at the campground. It's also a beer, bait, and tackle shop to get last minute goodies.

The last word on the river that I have heard is that it's full of smolts. There are scattered fish I'm sure, but the numbers of smolts are in the thousands.