Originally the area now known as San Gerardo was home to indigenous populations. Records show the names of Remigio Santana and Maria Jiménez “Chola”.
In 1930 the first white people arrived, and the native population moved into the mountains. The first whites to arrive were Reinecio Vargas and his wife Isolina Méndes Moro with their son Jose Manuel Vargas Moro, Porfirió Fonseca and his wife Ofelina Vargas «Bella», and Ramon Morales and his wife Lila Vargas and Francisco arrived. During the next few years other people arrived and everyone worked clearing the land to build their farms, or ranchos.
Time passed and the region changed considerably. The village of Canaán was established and in 1949 the house of Porfirio Fonseca was built that can be seen today, behind the church.
In 1950 a gentleman called Gerardo Valverde who was living in the nearby community of Herradura and was a devotee of Saint Gerardo, came to work on the property of Manuel Elizondo. The property was known as la garganta – ‘the throat’ and now called Montevideo, is situated in Chuma. They arranged for the property to be cared for on one condition: that the place be called San Gerardo. This was agreed and a likeness of the saint made that was paraded from Chimirol to the centre of San Gerardo, where a mass was said.
In 1955 Porfirio Fonseca, Adam Vargas, and Fernando Aryan among others made the first trail up Chirripó for the purposes of hunting. That same year the first school was constructed on the site of the current school dining room. The first teacher was Rosario Gamboa Muños, and the first school meeting with Jose Elizondo, Alfredo Quesada, Fernando Retana, and others took place in 1960. The first school patrons were: Joaquín Marín, Porfirio Fonseca, Antonio Elizondo and Fernando Arias.
- 1960 – the first store was built and owned by Ulysses Romero. It is now the family property of Ulysses Arias.
- 1964 – the town plaza was constructed through the joint efforts of Lesmes Marin and Jose Elizondo; and the first football team was formed.
- 1965 – the church was built – constructed of wood with the font of cement and stone and a pastoral committee was formed with the help of: Angel Vargas, Ivan Villarevia, Porfirio Fonseca, Lucas Day, Samuel Vargas, and Jose Elizondo. The first priest was Alexis Madrigal.
- 1965 – the first hiking trail up Mt. Chirripó was opened to the public on Saturday 17 July.
- 1968 – the community hall was built, and later remodeled in the 1990`s.
- 1970 – the church was remodeled in cement with the addition of a tower 18 meters high. Unfortunately, the tower was destroyed in an earthquake measuring 7.0 on the Richter scale on July 3, 1983.
- 1975 – the first health services were established in San Gerardo.
Today San Gerardo provides:
- Bus service six times daily to the town of San Isidro (1.25 hours by bus and 40 minutes by car)
- A plentiful and clean water supply
- A reliable electrical grid and a regulated public telephone system
- Health services delivered by a visiting doctor once per month, and emergency services at the hospital in San Isidro.
- Elementary education provided in a 4-classroom school with a dining room.
In this community most people earn a living through farming: growing crops – especially coffee, and managing dairy farms. Its main problem is road maintenance. The National Parks have developed many sport and cultural projects, and educational programs in the schools. In addition, this region has become an important tourist destination which has provided opportunities for hotel development and locally supervised services for Mt. Chirripó.