The Coalition Against Oil Pollution (CAOP) was founded in 1972 by Robert Lynette as a non-partisan organization to protect the waters of Puget Sound in Washington State. It opposed the opening on Puget Sound of oil ports and off-loading facilities that would connect with the proposed Northern Tier Pipeline. The coalition included both individuals and organizations, such as the Washington Environmental Council, and claimed to have support from environmentalists, tourist industry representatives, and commercial fishermen. CAOP constantly pushed for oil tankers to unload their crude oil at or west of Port Angeles, Washington, and won many legislative and legal victories. However, discord erupted within the coalition as many environmentalists began to feel that it only opposed oil tankers in Puget Sound, while remaining blind to the dangers of an oil pipeline across the state and supertankers in the Strait of Juan de Fuca.

Oil tankers in Puget Sound became a pressing issue during the energy crisis of the 1970s. The upper Midwest of the United States got much of its crude from Canada, which had already cut back on oil exports and announced that after 1982 it would no longer sell oil abroad. To compensate for the loss of Canadian oil, more crude had to be brought in from the Middle East, Indonesia, and the newly exploited fields of Alaska. Puget Sound was a logical receiving point for much of this oil, where there were already refineries and where a pipeline could be built to transport crude to Montana and Minnesota. The Northern Tier Pipeline Company was the first to propose a pipeline from Washington to the Midwest; it remained at the center of debates throughout the period.

The development of supertankers in the 1960s and 1970s exacerbated the situation. The coalition’s data showed that these larger ships not only spilled more oil, but were more prone to accidents. When Northern Tier planned to bring supertankers to Anacortes and Cherry Point in northern Puget Sound, the CAOP opposed it. In 1975 the coalition won its first major victory when the state legislature passed the Tug Escort Law, which banned oil tankers over 125,000 deadweight tons (dwt) from entering Puget Sound for at least two years (supertankers could be as large as 1,000,000 dwt). In 1976 the coalition won another victory when Governor Dan Evans amended the state’s Coastal Zones Management Plan to prevent construction of supertanker docks in Puget Sound.

Although the coalition had succeeded in gaining favorable legislation and policies from the state government, the political landscape changed dramatically in 1977, when Dixy Lee Ray became governor. Ray had close ties to the oil industry and promised to approve a supertanker port at Cherry Point. Fortunately for the coalition, the federal government took control of the issue, when United States Senator Warren Magnuson inserted an amendment into the Marine Mammals Protection Act of 1977 to prevent construction of a “superport” in Puget Sound.

While the CAOP did not want more oil tankers in Puget Sound, it had never opposed building a superport at or west of Port Angeles with a pipeline going around—but not across—Puget Sound. The reasoning behind its endorsement of such a compromise was that there was less chance of a spill if tankers did not cross into Puget Sound, and a spill in the Strait of Juan de Fuca would be much less harmful than one in Puget Sound.

As this compromise plan began to look more like a possibility after 1975, many people and organizations who had supported the Coalition Against Oil Pollution began to turn against it. Arguing that any oilport or pipeline would be too hazardous, an environmental group called No Oilport formed in 1975 to oppose the coalition’s compromise plan. Many citizens also opposed the CAOP’s compromise, which became apparent when 65 percent of Port Angeles voters showed their disapproval in a plebiscite. Despite opposition to an oilport, coalition founder Bob Lynette said, “The superport is a bitter pill that the people of Port Angeles are going to have swallow.”

In 1977 the Coalition Against Oil Pollution underwent changes in its leadership. Jay Pearson replaced Lynette as executive director and Mike Galvin became president. Friction between the coalition and its members continued to grow as it softened its stance further and considered endorsing a Northern Tier plan that would build a pipeline through, rather than around Puget Sound and Whidbey Island. In 1977 the Washington Environmental Council, over the coalition’s objection, passed a resolution to oppose any transshipment of oil through Washington State. In 1978 the Seattle Audubon Society withdrew its CAOP membership, and in 1979 the coalition’s lobbyist, Dan Seligman, resigned because he felt the coalition had abandoned its environmental goals to promote the Northern Tier pipeline.

In 1980 Northern Tier received the CAOP's approval to build a pipeline through Puget Sound, while eight environmental organizations, nine Indian tribes, and two local governments tried to block the plan through litigation. In 1981 Northern Tier suffered another setback when the Washington Energy Facility Site Evaluation Council recommended that Governor John Spellman reject the company’s application for a Port Angeles superport and underwater pipeline. Despite pressure from the U.S. President Ronald Reagan administration and many national politicians, Spellman rejected the application. As of 1997, no superport has been built on the Olympic Peninsula and only tankers under 125,000 dwt cross Puget Sound.

The Coalition Against Oil Pollution disbanded in 1982.