The Upper Canada District School Board (UCDSB), known as English-language Public District School Board No. 26 prior to 1999) is one of the largest public school boards in Ontario in terms of geographical area. It encompasses the counties in the easternmost portion of the province, including the cities of Brockville, Clarence-Rockland, Carleton Place, Cornwall, and Akwesasne. It covers most of the area surrounding - but not including - the city of Ottawa. Trustee elections are held periodically to elect new trustees.