downsizing at Ontario Hydro and the OPP resulted in the closure of the Ontario Hydro office and reductions in staff at the OPP. As a consequence, Warren's population suffered and many residents moved to larger centres such as Sudbury or North Bay. Demographics In the 2021 Census of Population conducted by Statistics Canada, Markstay-Warren had a population of living in of its total private dwellings, a change of from its 2016 population of . With a land area of , it had a population density of in 2021. Images See also List of townships in Ontario List of francophone communities in Ontario References External links Municipalities in Sudbury District Single-tier municipalities in Ontario