|Built in 1921, the 1.4-mile-long segment of the Old Spanish Trail (OST) immediately east of the Colorado River near Columbus, Texas, is a rare drivable section of an early Texas highway in its original rural setting. Known during various periods as Texas Highway 3, the Southern National Trunk Line, and U.S. 90, the highway served as a primary automobile route between Houston and San Antonio, and as part of a national highway running between St. Augustine, Florida, and San Diego, California. The western half-mile of pavement consists of 16-foot-wide concrete slabs, while the remainder of the road is asphalt on a gravel base, ranging between 16 to 20 feet in width. Bypassed in 1939, the segment is maintained as a county road, and serves as a remarkably intact example of state highway design built by the county with state and federal aid through the Texas Highway Department, established in 1917. The property is nominated to the National Register under Criterion A in the area of Transportation and Criterion C in the area of Engineering at the state level of significance.