Irisan was once a part of Tuba, Benguet as one of its Sitios. The head of the Sitio was called” Alkalde” in early 1920’s under the administration of the late Municipal Mayor Joaquin Smith then called Suakin Esmit.as per oral information by MS. Magdalena Niwane, the Sangguniang Bayan Secretary of Tuba,during the Spanish times the original name of Municipality of Tuba was the Township Twin Peaks .The Presidencia was located at Irisan .On December 11,1911 Executive Order no.11 was being issued, this created the Municipality of Tuba in place of the township of Tuba and the presidencia was still in Irisan .
Sometime in the later part of 1930, this was turned over to the City Government of Baguio as one of the barangays in the City. This was made possible through the effort of the late Benito Lopez during his term as Mayor of Baguio. However, there is no records or documents to show that Irisan and other sitios of Tuba were officially excluded as part of Tuba and made part of Baguio. (interviewed Magdalena Niwane, August 24,2000).Up to the present ,some Irisan residents still pay their taxes in Tuba.
Since then, it has been existing as a basic political unit in the Philippines by virtue of Republic Act no.3590 otherwise known as the Baguio Charter Act. The political units created under this act were termed “barrios” the act was amended by P.D. No.86 which contributed in the awakening of the interest of the people and broadened their participation in barangay affairs, the conduct of other matters interest. Presidential Decree no.86was further amended by P.D.557 which changed the term “BARRIOS” into Barangay due to the reason that barrios is of foreign origin.
Several years past, the Americans came and visited the place, they were astonished to see the Inhabitants crashing stone with the use of flat stones to extract gold, due to curiosity, the Americans asked what the settlers were doing and the Inhabitants answered in Ibaloi dialect, “ISHISAN” unable to understand well, the Americans pronounced “ISHISAN” as IRISAN which was adopted as the official name of the Barangay up to the present. ”ISHISAN when used as a noun is a wooden bowl to crush “sili” which serves as an appetizer and usually found in a typical Ibaloy home in Irisan.