The fonds consists of drafts and completed manuscripts and research materials including recorded interviews for Brennan's published books. Features drafts of his magazine stories and research notes; as well as copies and clippings and research materials for his works as journalist.

The fonds consists of alphabetical subject files about investments, newspaper publishing, sports, thoroughbred horse racing, the petroleum industry, local and national charities, and personal matters. Includes photographs of Max Bell, horse racing, newspaper subjects, and Calgary.