 West of Redford, FM 170 intersects Casa Piedra Road, an unpaved county route that provides access to the headquarters of Big Bend Ranch State Park and Marfa by way of RM 169.From this point forward to Lajitas, much of the road passes through Big Bend Ranch State Park where the road becomes more mountainous with sharp curves and steep grades.Within the park, there are several campgrounds, picnic areas, trail heads, and an old movie set.