Nearly 11 years after founding Summit Materials, Thomas W. Hill has announced his retirement as president, chief executive officer and director, effective September 1, after which he will assume a senior advisor role for the remainder of the year and serve in a consulting capacity through July 2023. His successor in the C-suite and on the Summit board is Anne Noonan, who will arrive with 30-plus years' of senior leadership experience at publicly traded companies and become the highest ranking female among major North American cement, aggregate and concrete producers.