I just got back from a recon run up to Chinook Pass. Searched out the campground, didnt think I knew were it was. Turns out, I've been there before.......
From Chinook Pass, look for Halfway Flat Campground. That is your landmark. The turnoff is about a half mile beyond that. You'll see signs for Little Naches Road and Litte Naches Recreation Area. turn left there. That is Forest Road 19. Kaner Flats campground is about 2 miles down on the right. If you continue on SR 410 and you go by Milk Flats Road, you've gone too far. If you pass Whistlin' Jacks, you've gone WAY too far.
If you are coming down Chinook Pass, note the road is washed out about a half-mile down from the parking area at the top of the pass. There is a one-lane detour at that spot, you'll have to stop and make sure traffic is clear before proceeding. Part of it is on the shoulder so you guys with trailers and campers and motorhomes need to be careful. It's narrow and bumpy. The rocks are right_there. DOT hasnt started repairs other than setting up the detour. Probably waiting for a special gas tax next year before repairs can begin....
From Yakima, look for Milk Flats road, past Whistlin' Jacks. That is your landmark. Little Naches Road is about a quarter mile beyond. Turn right on Little Naches Road.
The campground hasnt been mowed and the grass is tall. So there is a higher fire danger. The fee is $10/night/vehicle $5 for each extra vehicle/night.
When I was coming back, there was an ugly accident at Horseshoe bend, which is about mile or so from the US12/SR410 Wye. A motorcycle lost it in the curve, dumped his bike and slid into the guardrail. There were about a dozen State Patrol/Sherrif/DOT vehicles there, and they had the pavement measured out with a tape. Not Good.
--Karl