What is the cost of parking your car here for a couple days while going backpacking into the backcountry?

There is parking at the Rush Creek Trailhead where you should be able to park your car for free. Can also park it along the highway if you're ok leaving it there.

It's something like $23 per night. And less if you have a pass for being disabled $9 per night unless it's changed from last year Enjoy! State Park ran.