Nestled in the foothills of the Canadian Rockies amid some of Alberta’s finest ranch country, the area formerly known as the Town of Black Diamond sits at the crossroads of Highway 22 – known as the Cowboy Trail – and Highway 7, within the Calgary Metropolitan Region. The community takes its name from coal deposits that were once found near the original town site, and its first post office opened back in 1907. Black Diamond incorporated as a village on May 8, 1929, and after nearly 26 years in that status, it became a town on January 1, 1956. On January 1, 2023, Black Diamond amalgamated with its neighbouring community of Turner Valley to form the new Town of Diamond Valley, following a Province of Alberta order in council issued on May 25, 2022. The merger had been the subject of decades of discussion, including a 2007 plebiscite in which Turner Valley residents supported amalgamation while Black Diamond residents did not. The prospect of potential cost savings of roughly $1 million per year ultimately helped move the amalgamation forward without a further public vote.
Before amalgamation, Black Diamond had a population of 2,730 according to the 2021 Census, a modest increase from 2,705 recorded in 2016 and up from 2,373 in the 2011 Census. The town covered a land area of 6.82 km2, with a population density of around 400 people per km2. Black Diamond and Turner Valley operated as sister towns, and the area is served by a hospital, shops, hotels, an elementary school covering kindergarten through grade 6, a high school for grades 7 through 12, a hockey rink, and a Boys and Girls Club. Connecting the two former towns is the Friendship Trail, a 3-kilometre path running alongside the roadway between them. Governance of the Black Diamond area now falls under the Diamond Valley Town Council, with Brendan Kelly having served as the final mayor of the standalone Town of Black Diamond.