Morrison–Knudsen

Morrison–Knudsen (MK) was an American civil engineering and construction company, with headquarters in Boise, Idaho.

MK designed and constructed major infrastructure throughout the world and was one of the consortium of firms that built Hoover Dam, San Francisco–Oakland Bay Bridge, the Trans-Alaska Pipeline, and many other large projects of American infrastructure.

MK's origins date to 1905, when Harry Morrison, Chairman and President met Morris Knudsen while working on the construction of the New York Canal (Boise Project) in southwestern Idaho. Morrison was a 20-year-old concrete superintendent for the Reclamation Service; Knudsen was a forty-something Nebraska farmer (and Danish immigrant) with a team of horses and a fresno scraper.

Their first venture together was in 1912, on a pump plant in nearby Grand View for $14,000; they lost money but gained experience. MK earned some revenue in 1914, when they constructed the Three Mile Falls Diversion Dam, south of Umatilla, Oregon. For several years, the firm built irrigation canals, logging roads, and railways; they incorporated in 1923, the year gross revenues topped $1 million. MK reached a significant milestone with its joint venture in the construction of Hoover Dam (1932–35).

During World War II, MK built airfields, storage depots, and bases throughout the Pacific, and built ships along the West Coast. Japanese forces captured 1,200 workers, including many MK employees, stationed on Midway and Wake Islands in late 1941. After the war, MK expanded into a variety of international construction fields.

MK won contracts for many domestic and foreign Cold War projects. It built the locks on the St. Lawrence Seaway, the Distant Early Warning Line system, also known as the DEW Line or Early Warning Line, Minuteman missile silos, NASA’s Kennedy Space Center, and over 100 major dams. In 1946, King Mohammad Zahir Shah and the Kabul government tasked Morrison-Knudsen with a large array of construction tasks in Afghanistan, including irrigation and a hydroelectric dam in the Helmand Province area. Morrison was featured on the cover of Time magazine on May 3, 1954, and the article claimed Morrison was "the man who has done more than anyone else to change the face of the earth."

In the late 1950s, MK constructed the railroad causeway that spanned across the Great Salt Lake in Utah. The Lucin Cutoff causeway allowed trains to operate at full operating speeds instead of the slower speeds required to safely travel over the deteriorating wooden trestle crossing parallel to it. The causeway is estimated to have used 65 million tons of rock and gravel.

In the 1950s it was involved in the construction of the Rimutaka Tunnel in New Zealand, the longest rail tunnel in the southern hemisphere. In the wake of the Christmas flood of 1964, MK returned the Northwestern Pacific Railroad main line to operation in only 177 days. This involved building 100 miles of track, 30 miles of access roads, and three bridges. In the late 1960s and early 1970s, MK was involved in the construction of the Hamersley & Robe River and Mount Newman railways in the Pilbara region of Western Australia.