He became an Eagle Scout in 1946 and is a recipient of the Distinguished Eagle Scout Award.
He graduated from Colorado State University in 1953 with a bachelor's degree in civil engineering.
Scott was first elected to the Peter Kiewit Sons' Incorporated board in 1964. In 1979, he was elected President. When Peter Kiewit died later that same year, Scott was selected to succeed him as chairman.
Scott's second wife Sue Scott had been a good friend of his first wife, Carolyn, who died in 1983, but did not know Walter. They married in 1987 at their place of worship, Countryside Community Church. Suzanne died in 2013.
In 1996 Scott acquired the original sales document of the Louisiana Purchase for his private collection.
Scott was the 1997 recipient of the Horatio Alger Award.
Scott is chairman of Level 3 Communications. The corporation is one of the firms created by the 1998 separation of the two operating divisions of Peter Kiewit Sons' Inc. Since the split-off, Scott now serves as chairman Emeritus of Peter Kiewit Sons', Inc.
In June 2010, when Warren Buffett appealed to him to join the Giving Pledge, he partially accepted, stating that after his death his remaining estate will go into his eponymous foundation.
In November 2016 it was announced Scott would be donating $53.3 million to Colorado State University School of Engineering, CSU's largest ever gift, and that the College of Engineering at CSU will be renamed the Walter Scott, Jr. College of Engineering, becoming the only named college of engineering in the state of Colorado.
