You can put in at the upper hatchery right below Merwin dam and drift down to the lower hachery. But the fish may not be that high up the river yet. Or you can put in at the lower hatchery and drift to the golf course or island ramp. I like the lower hatchery to the island ramp float alot lots of nice water to fish the put in and take out is on the north side of the river. Go up thru Woodland on the Lewis river road. You will see a sign for the ramp if you see the Echo RV park you have gone to far. If you drift to the island ramp take a close look at the river so you do not miss it on the way down. you will have to push your boat just a bit.
At the hatchery you may need a 4x4 to get your boat in ( lots of loose gravel ) Good luck.