Several features are identifiable in this photograph of the southern tip of coastal Texas—the southern end of South Padre Island; the southern end of Laguna Madre; the southern terminus of the Intracoastal Waterway; and the Brownsville Ship Channel. The coast adjacent to the Gulf of Mexico consists generally of a mixture of light sandy soils and rich brown soils that overlay the clays and sands of the Rio Grande floodplain. The mottled appearance of the landscape, showing an assortment of tidal flats, swampy areas, and sandy terrain, makes it impossible to discriminate where the Rio Grande flows through this broad delta. The sediment pattern in Laguna Madre and a portion of the dredged Intracoastal Waterway (left center) indicate that sandy soils are transported by air and water throughout the coastal region of South Padre Island. Only a single runway of the airport east of Brownsville is discernible (right bottom corner).