Osage Hills State Park lies just west of Bartlesville in the heart of the Osage Nation in northeast Oklahoma. Lush forests, rocky bluffs and calm waters fill 1,100 acres, and fall foliage turns vivid yellow, orange and red. Trails over rocky, hilly terrain challenge hikers and mountain bikers, and visitors may spot white-tailed deer or wild turkey. The park has cabins and campsites for overnight stays.