On March 13, 1968, Atlantic Richfield Oil Co. (later ARCO) and Humble Oil and Refining Co. (later Exxon) announced the discovery of large deposits of oil on the North Slope of Alaska. These companies and several others began planning the Trans-Alaska Pipeline System to move oil from the north side of Alaska 800 miles to a seaport on the Gulf of Alaska. The Alyeska Service Pipeline Co. was formed in 1970 by the participating oil companies to build and operate the system.
Beginning in April 1970, environmental groups attempted to block the project by filing lawsuits. The pipeline consisted of a 48-inch diameter steel pipe that crossed three mountain ranges and more than 800 rivers and streams. Ultimately, Alyeska obtained 515 federal permits and 832 state permits for the project. Thirty-one persons lost their lives in construction accidents.
Beginning in 1971, the Boeing Co. reduced its workforce from approximately 103,000 to approximately 39,000 resulting in a double-digit unemployment rate in King County. In 1973, after the Yom Kippur War in the Middle East resulted in a serious world-wide gasoline shortage, Congress passed the Trans Alaska Pipeline Authorization Act which removed all hurdles to construction. People and supplies immediately began to flow through Seattle to Alaska.
The first oil from the North Slope reached Valdez via pipeline on July 28, 1977. In 2001, the pipeline carried approximately 17 percent of the U.S. oil supply.