Rooster Rock is an easy 4 point summit in Washington. I was able to activate Rooster Rock while out camping with my family at nearby Chehalis RV and Camping Resort. Looking for summits nearby to activate using my SOTA Spotter app Rooster Rock and 3780 Top Loaded Mountain showed up and both had been activated already. Usually that's a good sign that there is a good way to the summit.
The forest roads are in good shape. Good for a passenger vehicle. Google maps did a great job of getting me to the summit from the RV resort. I'm sure it will do the same for you from your QTH. I will add the meaty part of the directions here...From the RV resort I headed East on Centralia Alpha Road to WA-508E. Make a sharp left onto WA-508E. Stay on 508E for about 6.5 miles to Forest Rd 71. Turn left onto Forest Rd 71. Follow 71 for about 4 miles to 46.63182 -122.47039. Turn left here and head up to the gate. The gate is at 46.63298 -122.46884. From here it's an easy 0.75 mile hike to the summit. There's a radio relay station up top, KXXO-FM Olympia. I'm not sure if it's still operational because the fence aound it was torn down.
Nice quiet summit. If you have time you can travel further up NF-71 and activate 3780 Top Loaded Mountain, W7W/PL-089.
Also consider activating 3780 Top Loaded Mountain while in the area.
