In 1952, the boundaries were narrowed significantly to include only the city of Sudbury, the geographic township of McKim and the town of Copper Cliff.

In 1996, it was redefined as the part of the City of Sudbury north of a line drawn from east to west along Highway 69, south along Long Lake Road, and west along the north boundary of the geographic Township of Broder.

In 2003, the riding expanded geographically to include the former town of Walden, now part of the city of Greater Sudbury.

Following the 2022 Canadian federal electoral redistribution, the riding will gain Nickel Centre, Wanup and the remainder of the former city of Sudbury from Nickel Belt, and will loses all of its territory west of Highway 144 to the new riding of Sudbury East—Manitoulin—Nickel Belt.

According to the 2021 Canadian census[3] Ethnic groups: 77.9% White, 12.3% Indigenous, 3.8% Black, 2.8% South Asian Languages: 70.0% English, 16.6% French, 1.7% Italian Religions: 60.0% Christian (41.1% Catholic, 3.9% United Church, 2.9% Anglican, 1.4% Lutheran, 1.2% Pentecostal, 1.1% Baptist, 8.4% Other), 1.4% Muslim, 1.2% Hindu, 35.3% None Median income: $42,400 (2020) Average income: $53,450 (2020) Riding associations are the local branches of political parties: This riding has elected the following members of Parliament: