On May 13, 1883, Murdoch moved to Calgary. This was just months before the Canadian Pacific Railway had reached the community in August. In Calgary, he started a successful harness shop. As Calgary was at its early stages, his main clientele were the North-West Mounted Police based in Fort Calgary and Blackfoot Indians who had a reserve nearby. He was on good terms with the Blackfoot, and had learned to speak their language.
In the community, Murdoch was involved with the Masonic Lodge and the Orange Order in Canada, literary and history societies, volunteer fire brigade, was one of the founders of Calgary's Presbyterian Church and the first President of the Calgary St. Andrew's Society. Being one of the first permanent businessmen in Calgary, he was an active participant in securing the incorporation of Calgary from the government of the North-West Territories in November 1884. On December 4, 1884, he became the first mayor of the Town of Calgary. He held this post until October 21, 1886. Murdoch was disqualified from the 1886 election after an unsubstantiated allegation was made that he had tampered with votes.
Murdoch also served as town Councillor from 1889 to 1890 and city Alderman from 1895 to 1896.
