Mr. Johnston has been a director of Horizon North since May 29, 2020 and was appointed to the Board of Directors of Horizon North as a Dexterra Nominee upon completion of the Transaction. Mr. Johnston has been a director of Dexterra since March 2018. Mr. Johnston has held a number of distinguished management and leadership positions in academia and government, including acting as the 28th Governor General of Canada from 2010 to 2017. Mr. Johnston has held a number of academic positions, including as principal and vice-chancellor of McGill University for fifteen years and as the president and vice-chancellor of the University of Waterloo. Mr. Johnston has also served on numerous provincial and federal task forces and committees, acted as president of the Association of Universities and Colleges of Canada (now Universities Canada) and of the Conférence des recteurs et des principaux des universités du Québec. Mr. Johnston is a member of the Order of Canada and was promoted to companion, the Order’s highest level, in 1997. Mr. Johnston was also the first non-U.S. citizen to be elected chair of Harvard University’s board of overseers.