Harold More Cooper was born in 1886 in North Adelaide and educated at the Queen's School, North Adelaide. He began his working life in about 1904 with the Eastern Extension Cable Company, Tennyson. From 1926 until the outbreak of the Second World War he operated an amateur experimental wireless station at Glenelg, work which contributed to research in radio communications. During the Second World War Cooper was active in the Royal Australian Navy Volunteer Reserves and from 1941 took part in naval patrols of Gulf St Vincent. He continued to serve the Navy in a voluntary capacity until 1954.

Hans Mincham states that Cooper's interest in stone artefacts dates from1934, when he read Walter Howchin's Stone Implements of the Adelaide Tribe. In the same year Cooper found a significant archeological campsite at Hallett Cove, south of Adelaide. He was to visit Hallett Cove over 200 times over the next three decades, keeping meticulous records and contributing artefacts collected to the South Australian Museum collection. He also conducted extensive fieldwork on Kangaroo Island. His work in the Flinders Ranges and north as far as Maree included documenting rock carvings and paintings.

Cooper began work for the South Australian Museum in an honourary capacity in 1934. He was appointed Assistant Ethnologist in 1941, a title which was later changed to Assistant Curator of Anthropology. After his retirement in 1957 Cooper again worked on an honorary basis until his resignation due to ill-health in May 1969. He also resigned from his position as an inspector under the Aboriginal and Historic Relics Act in May 1969. He had ceased fieldwork some time in 1968 due to ill-health.

Cooper's publications in archaeology and anthropology include articles on Hallett Cove, Kangaroo Island, the Lower River Wakefield, and Australian Aboriginal material culture. He was co-author of Hallett Cove: A Field Guide (1970, Adelaide, The South Australian Museum), published after his death. His book Australian Aboriginal Words and their meanings, first published in 1948, went through many editions and remained a popular work while in print. Cooper contributed thousands of items to the South Australian Museum's collection, mainly stone artefacts from archaeological sites.

Cooper had an active interest in natural history, and collected across a number of fields including botany, icthyology and entomology. Among those species he collected were land snails, and two of the three new species he discovered bear his name: Sinumelon cooperi, from Kangaroo Island, and Pleuroxia cooperi, from the Flinders Ranges. A botanical article based on Cooper's work, 'Notes and Observations on Calostemma purpureum' (The South Australian Naturalist, 45 (4), June 1971, pp. 112-114), was prepared by Mrs Maragret Nobbs and published after his death.

Cooper's interest in maritime history and exploration led him to research, write and publish three books: A Naval History of South Australia (1950, Adelaide); French Exploration in South Australia (1952, Adelaide); and The Unknown Coast (1953, Adelaide), (on Flinders' explorations in South Australian waters). He also published The Unknown Coast (A Supplement) (1955, Adelaide). Cooper's interest in matters maritime was personal as well as historical; he had his own boat since the age of 18.

Cooper died on 14 May 1970. Most of the material in AA 64 Cooper Collection came to the South Australian Museum from his estate. Included is also some supplementary material and some material generated in the 1980s relating to a proposed republication of Australian Aboriginal Words and their meanings. In October 1970 the Museum purchased a further 59 items relating to Cooper - 58 offprints and one notebook in the form of an address book. The offprints are now part of the offprints collection.

Cooper's field records were apparently 'inadvertently destroyed during the settlement of his affairs following his admission to hospital'. ('Notes and Observations on Calostemma purpureum', The South Australian Naturalist, 45 (4), June 1971, p. 112).

Note that a collection of printing blocks relating to A Naval History of South Australia previously held by the South Australian Museum Archives were transferred to the collection of the South Australian Maritime Museum in June 2005.

Related Collections in the South Australian Museum Archives: HE Burrows AA 45