[4] Jack Longland described the greatest rock face in Wales, Clogwyn Du'r Arddu, as "Colin’s Cliff".
[5] Kirkus' series of new routes on "Cloggy" was unparalleled until the emergence of Joe Brown, 20 years later.
[citation needed] In 1933 Kirkus was a member of Marco Pallis's expedition to the Gangotri area of the Himalaya and the team climbed several peaks.
[6] During the expedition Kirkus and Charles Warren made a pioneering alpine-style ascent of the central or 'second Satopanth peak' which is now known as the 6,454 metres (21,175 ft) Bhagirathi III;[2][7] Kirkus' account of the climb is included in Pallis's book Peaks and Lamas.
He was one of four brothers, all of whom saw flying service in the RAF, and three of whom were killed in action in the Second World War.