Morrison-Knudsen (also known as M-K) was an engineering and construction firm founded in Boise in 1912. Created by Morris Hans Knudsen and Harry Winford Morrison, they completed heavy construction projects across the United States as well as 71 foreign countries. M-K is mostly known for their participation in the construction of the Hoover Dam, San Francisco Bay Bridge, Vehicle Assembly Building at the Kennedy Space Center and 153 miles of the Trans-Alaskan pipeline.

In South America, they are known for partnerships in the Cerrejón Coal Mine in Colombia, the Itaipu hydro electric dam on the Paraguay-Brazil border, and contracts for segments of the Trans-Andean highway. In South-East Asia, M-K was a major partner in RMK-BRJ, a private company joint venture to build infrastructure for the United States military during the Vietnam War. In Central Asia, North Africa, and the Middle East, M-K built irrigation systems, airports, and military infrastructure to aid the U.S. in Cold War diplomacy from the late 1940s through the 1970s.

When energy shortages and Cold War détente lowed demand for international construction, M-K shifted to domestic and foreign diversification including: mass transit, resource extraction, residential property development and locomotive manufacturing. By the late 1980s and into the 1990s, M-K experienced a decline in revenue and in 1996 the company was sold to Dennis Washington, owner of a smaller but similar firm. After a few years of recovery and stabilization. Morrison-Knudsen Corp. was renamed Washington Group International. In 2007 that company was sold to United Research Services (URS).