Summit Materials Inc
A Denver-based maker of the building blocks of roads and buildings — crushed stone, sand, gravel, cement, ready-mix concrete, and asphalt — used in public infrastructure and construction projects across the United States and British Columbia. Founded in 2009 by Tom Hill, a former CEO of Oldcastle, the company grew by buying up local materials firms, starting with Kansas's HAMM Companies. Its name nods to the founders' ambition to reach the top of the industry.