Garigal and Cannalgai were the Aboriginal groups living in the Pittwater and Northern Beaches area near Sydney in 1788. They were part of the Guringai language group. Their coastal environment provided an abundant supply of their staple diet, seafood. Birds, reptiles, marsupials, roots, berries, fruits and nuts were also part of their diet, and were no doubt gathered from the surrounding Pittwater bushland. During the years 1789-1790 many of these people died from introduced diseases, others moved away in the face of the advancing tide of European settlement.

Katandra Bushland Sanctuary is situated in the Pittwater LGA on the face of the Ingleside escarpment, overlooking the Warriewood Valley and the seaside suburb of Mona Vale. The land presently comprising the Sanctuary was part of a grant in 1859 to a Robert McIntosh of Botany. It changed hands in 1885, and again in 1913 when a sub-division was effected. Twenty-five acres was purchased by a Roseville businessman, Harold Alfred Seymour, on 3rd December ,1946

Mr Seymour took up residence on his land, living first out of his car, later in a succession of army-surplus huts, before having a brick and stone cottage built . He delighted in his surroundings, enjoying both the native flora and fauna, including 'Koala', still to be seen. He loved to share his 'bushland' with friends, taking them for long rambles through the undergrowth, as initially there were no paths to follow. He became well respected for his knowledge of indigenous flora, thus earning the friendship and support of people well known in the world of natural history and conservation. Alarmed at the advancing tide of settlement, Mr Seymour, in 1964, offered eighteen acres of his land as a gift to the people of NSW to establish a wildlife reserve for the promotion, study and preservation of native flora and fauna. He chose the name ‘Katandra’ - meaning ‘song of birds’ - and with a band of friends and supporters formed the ‘Katandra Bushland Club’.

The Katandra Bushland Sanctuary was officially gazetted Reserve No 86487 on 6th October 1967. Seven Trustees responsible for the management of the sanctuary were appointed in 1968. The first President of the Trust was Mr R H Anderson, Director of the Royal Botanical Gardens, Sydney. Katandra was officially opened by the Minister for Lands, the Hon. Tom Lewis on 8th September 1968.

Harold Seymour later sold a further five acres to the Crown for addition to the Sanctuary, to which the NSW Government added some adjacent Crown Land and unmade Road Reserve, so that the reserve now covers approximately 28 acres. The Katandra Bushland Club is now known as the Friends of Katandra and has continued its support of the Sanctuary into the 21st Century. Harold Seymour died at Katandra on 16th December, 1987, the eve of his 94th birthday.