Two distinctive subaerial physiographic features that form a substantial portion, by area, of most barrier islands along the Texas coast are the washover fan and the tidal delta. Volumetrically, washover fan deposits and tidal delta deposits form a significant part of each barrier island. The facies types characteristic of these features, together with their geometry and relationships to sediment of the barrier island nucleus on one side, and bay margin on the other, have not been previously described. The object of this study was to describe and explain the character, geometry, and development of facies that typify a prominent subaerial washover fan and its adjoining subaerial tidal delta on St. Joseph Island, Aransas County, Texas.