From jct US 95 & Hwy 5: Go 5 mi E on Hwy 5.
Good place to come during bird migration. Cottonwood Creek is lovely, but I'm pretty sure it has an alias: Mosquito Hollow. It does have a peaceful sound to it, when the truck traffic isn't too heavy.
Have camped here a few times and it was pleasant. Never very far away from wildlife viewing and fishing.
We rented a cottage that was nice. It was hot though that week and there was little relief until about 2am in the morning. The beds in 2bedrooms are full size beds, so a little to small for 2 adults. When we called asking questions about what was available in the kitchen, the staff wasn't very knowledgeable. We packed for one time of cooking and got there and wasn't prepared for really was there. The views though from the fully screen porch over looking the lake was out of this world, my wife and I had tea both morning and evening while reading.
Yes, this is a “natural” state park, NOT a RV resort. So plan on getting back to nature here. I have great memories here. Love the rustic but very beautiful setting. This state park is not meant for large RVs, so if you want class and style, go somewhere else. The paved bike path is the main attraction and very nice.