Also know as "Riverside State Park ORV Area".  The ORV park is about 600 acres with a riding mixture of hill climbs, play areas, and trails winding through the ponderosa pines.  Amenities include loading ramps, picnic shelters, a beginners area,  and restroom facilities.

Along with a current ORV sticker on your bike, a Washington State Discover Pass is required for parking.  You will need a Discover Pass before you get there because there is no place close to buy one and you will get ticketed without one.