After the business failed, he took work as a stable hand at Kilkenny, then as a striker for a blacksmith before being employed for a longer term as a conductor on the horse tram service, continuing when the line was electrified.

Suffering poor health from the tropical climate and hard work, Mountford, then thirty-three, was posted back to the Adelaide GPO workshops where his family lived at 52 West Street, Torrensville.

When Florence died aged 34 on 30 May 1925,[2] Mountford, seeking distraction, revived his interest in indigenous culture and artworks in particular, and while staying with his father in Dawson they found at nearby Merowie Springs a rock with dozens of carved grooves which he traced and photographed.

In 1935, he took on the role of secretary for a board of inquiry tasked with investigating reports of mistreatment of Indigenous Australians in the Northern Territory, specifically at Hermannsburg and Uluru by mounted constable William (Bill) McKinnon.

[6] In the same year, he joined an expedition organised by the University of Adelaide's board for anthropological research to the Warburton Range in Western Australia, alongside Tindale, C. J. Hackett, a physical anthropologist, and E. O. Stocker, a cine-photographer.

The results of this endeavor were showcased through photographic exhibitions and a prize-winning colour film created in 1940, which subsequently became the foundation for the book Brown Men and Red Sand.

[9] With the support of the Australian Director-General of Information, Mountford conducted two lecture tours in the US in 1945 and 1946, drawing an audience of four thousand Society members in Washington DC,[10] and an account of his expediitons was featured in the January 1946 edition of National Geographic.

[11] This eventually paved the way for the establishment of the American-Australian Arnhem Land Scientific Expedition of 1948,[12] comprising American and Australian experts in various fields, including flora, fauna, archaeology, anthropology, photography, filmmaking, and health.

[13] With sponsorship from the Commonwealth Department of Information, Mountford returned to Oenpelli in 1949, accompanied by professional photographer W. M. Brindle, and they produced the book Australia: Aboriginal Paintings, Arnhem Land, one of UNESCO's world art series.

[24] Mountford's articles on allied subjects were published in The Bulletin, Walkabout,[25] Pacific Islands Monthly, Australasian Photo-Review and others now digitised and publicly accessible at the National Library of Australia.

His publications contributed to the global exposure of Aboriginal art and the development of an international market for it and, as noted by Berndt, such artworks were sold for increasingly high prices in the US and London by 1954.

He concluded that a number of photographs, drawings and descriptions of persons, places and ceremonies featured in the book held deep religious and cultural significance to the plaintiffs, and that their publication could harm the community.