In Luttes v. State, 159 Tex. 500, 324 S.W.2d 167, 191 (Tex. 1958), private landowners sued the State in a trespass to try title action of 3,400 acres in Cameron County, about fifteen to twenty miles north of Port Isabel and fifteen miles south of Port Mansfield. See Appendix 1. In that case, the Laguna Madre bordered the land in dispute on the east. Where the mainland met the shore, there was an abrupt change in the angle of elevation, character, and appearance of the soil, including a well-marked beginning line of sand followed by grass and vegetation. Luttes, 324 S.W.2d at 168. This vegetation or bluff line appeared to be the land's original eastern boundary. Luttes, 324 S.W.2d at 168-69. The landowners claimed, however, that the bluff line had ceased to be the boundary, because by process of accretion the mud flats now covered the area that was once covered by water. Lutts, 324 S.W.2d at 169. Thus, the landowners in Luttes claimed that the boundary had moved further east and that they now owned the mud flats.