Situated northwest of Spokane, Riverside State Park stretches along the Spokane River and covers some 14,000 acres. It’s Washington’s largest, beating Mount Spokane by a few square feet. Trail 25, so-named due to it’s 25-mile length, closely hugs the river to the Nine-Mile area, then loops back atop the high bluffs and along the base of the basalt cliffs overlooking the park.