Located in south central Cameron County, the town was named for the fresnos (ash) trees scattered in the woods and along streams. In 1912, Lon C. Hill, an early land owner, formed a company to develop a canal system that would use the Rio Grande River to irrigate land for farming. Railroad construction in the early 1900s began to bring settlers to the area, and by 1915 a post office was established. Because of the fertile, irrigated land, farm products increased and, with the long growing season in the Valley, farming flourished. Today, the city is still surrounded by fertile farm/ranch land. Major crops are cotton, sugar cane, sorghum and citrus.