Ten (10) members of the U.P. Mountaineers (UPM) Exploration Team reached the summit of Mt. IRID on March 11, 1979 at exactly 1711 Hours/5:11 PM. Climb duration: 09-12 March 1979 in clear weather and zero casualty. Entry and exit route used: Tanay town poblacion, Rizal Province (CALABARZON Region), Luzon Island, Philippines.