Port Mansfield Channel or Mansfield Cut is an artificial waterway encompassing the Laguna Madre positioned at the 97th meridian west on the earth's longest barrier island known as Padre Island. During Post–World War II, the tidal inlet was dredged as a private channel differentiating North Padre Island better known as Padre Island National Seashore and South Padre Island. The navigable waterway was channeled during the late 1950s ceremoniously cresting the intertidal zone of the Gulf of Mexico by September 1957 on the Texas Gulf Coast.