Junction Spur #600. = Photo view from highway East to Brownsville, Texas. West to Hidalgo, Texas. South to Mexico / USA border crossing at International Bridge. Note: Highway 281 East of this point is called the Texas Tropical Trail. Texas Tropical Trail (The Old Military Highway) Highway 281 as well as being called "The old Military Highway", and is part of the "Texas Tropical Trail" the highway is also part of "The Great Texas Birding Trail"