The fonds consists of business correspondence of dairy farm operations and livestock export business; Hays Converters breeding and performance records and marketing correspondence; personal correspondence, invitations, memberships, and records of organizations in which he was involved; Hays' Stampede Breakfast guest lists and financial records; and photographs and slides of family, livestock, Stampede activities, and Harry as mayor, Minister of Agriculture and Senator.
Records related to the following subjects are also in the fonds. See inventory for details: Alberta Beef Cattle Performance Association, Alberta Egg and Fowl Marketing Board, Alberta Egg and poultry Producers' Association, Alberta Jersey Cattle Club, Alberta Livestock Associations, artificial insemination, Bar U Ranch, Beagle Ranch (Lomond), Archie Boyce, Boys' Clubs of Calgary, Calgary Board of Trade, Calgary Chamber of Commerce, Calgary Golf and Country Club, Calgary Power, Canada Permanent Trust, Canadian Charolais Association, Canadian Hackney Society, Canadian Hays Converters Association, Canadian Marchigiana Association, Canadian Percheron Association, Canadian Swine Breeders' Association, CFAC radio, Chianina cattle, Clear Lake Ranch (Stavely), Bob and Ann de Vries, Jean Frydman, Jack Gallagher, Grace Hospital (Calgary), Daniel P. Hays, Thomas E. Hays, Hays and Earl Ltd., Hays-Moore and Earl Ltd, Holstein-Friesian Association of Canada, Home Oil Co., Hutterites, irrigation, Jenkins Groceteria, Jersey cattle, Lakeside Feeders (Brooks), Lester B. Pearson College of the Pacific, Lethbridge Central Feeders' Association, J. Russell Love, Natural Resources Growth Fund, Old Man River Hereford Ranch (Pincher Creek), Paragon Properties, Pekisko Gas Co-op, Lloyd Pickard, Pincher Creek Ranches, Rotary Club of Calgary, Running Bar X Ranch (Medicine Hat), Kathleen Whitton Ryan, sheep, Simmental cattle, United Dairies, Universal Semen Service (Cardston), V Bar V Ranch (Wardlow), Western Breeders Service (Balzac), and S.B. Williams.