San Juan Plantation, on the Rio Grande near San Juan, Hidalgo County, is recognized as a historic landmark by an official Texas historical marker on the plantation headquarters. The founder and developer of this, the earliest and largest plantation in an area at one time considered suitable only for grazing, was John Closner, a law enforcement officer for twenty-eight years, sometimes called "the father of Hidalgo County." He began buying land in 1884, and by 1904 San Juan Plantation, so named by Mrs. Closner, comprised 7,000 acres. The total eventually reached 45,000 acres. By 1895 Closner had installed a pumping plant and constructed a network of canals and laterals for the first irrigation system from the Rio Grande in the area. The equipment came by water to Port Isabel and was hauled by wagon the fifty-odd miles to the plantation. Closner was the first in that area to raise alfalfa, of which he had 700 acres flourishing under several cuttings a year; the first to experiment with tobacco crops; the first to experiment with sugarcane by cross-planting hybrid cane seed from Mexico with seed from Louisiana; and the first to experiment with commercial crops of vegetables, fruits, melons, and nuts. His findings in such diversified farming set a wide example. The first telephone line in that area, installed in 1902, connected Closner's home in Hidalgo to the headquarters of the plantation. Later he constructed a line to McAllen; the Hidalgo Telephone Company was formed with Closner as president. As the plantation progressed, the number of families of workers increased. A substantial school building was erected and equipped at a cost of $1,500 for the children of the plantation. Sugarcane from the plantation won the gold medal at the 1904 Exposition in St. Louis for the finest sugarcane in the world. At that time the plantation devoted 800 acres to sugarcane, which was processed into piloncillo (cones of coarse brown sugar) for the native trade on both sides of the Rio Grande. Production of sugar processed from a 250-ton mill began when boilers for the mill arrived after many transportation difficulties and at great expense. In 1908 Closner incorporated the Rio Grande Valley Reservoir and Irrigation Company, with J. R. Alamía and W. L. Lipscomb, to expand irrigation efforts in the area; but the plan never materialized. In 1910 he sold his plantation for $250,000. By 1921 sugarcane was gone from the Valley, but cotton, citrus fruits, and vegetables became important products because of the rich soil, climate, and irrigation, assets that Closner had recognized in the mid-1880s. A historical marker was placed at the site of San Juan Plantation in 1964. In 1990 the site was privately owned.