Monte Alto is located on FM-88, approximately 7 miles north of Elsa. In 1926, the St. Louis, Brownsville, and Mexico Railway built a line through Monte Alto and a siding called Rollo nearby. In 1947, Monte Alto had 2 businesses and a population of 25.
The Monte Alto Independent School District was established on 08/01/53. Monte Alto had a population of 430 in 1964, but no known businesses. The Missouri-Pacific rail line from Monte Alto to Edcouch was abandoned in 1968, at which time the population was listed at 625.
The 1990 census counted Monte Alto as having a population of 1,769. The 2000 census count has not yet been released, but the community now has a couple of convenience stores, a clinic, an auto repair shop, and a large food processing and warehouse center. The surrounding area is known for its agriculture.