La Grulla is a city in Starr County, Texas, United States, founded by Juan Santiago Longoria in 1836. The population was 1,222 at the 2020 ce…La Grulla is a city in Starr County, Texas, United States, founded by Juan Santiago Longoria in 1836. The population was 1,222 at the 2020 census. La Grulla is located at 26°16′9″N 98°38′49″W / 26.26917°N 98.64694°W.