Tosco was an independent US based petroleum

Petroleum

Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

 refining and marketing corporation. It was founded in 1955 in Santa Monica, California

Santa Monica, California

Santa Monica is a beachfront city in western Los Angeles County, California, US. Situated on Santa Monica Bay, it is surrounded on three sides by the city of Los Angeles — Pacific Palisades on the northwest, Brentwood on the north, West Los Angeles on the northeast, Mar Vista on the east, and...

 by A&P

The Great Atlantic & Pacific Tea Company

The Great Atlantic & Pacific Tea Company, better known as A&P, is a supermarket and liquor store chain in the United States. Its supermarkets, which are under six different banners, are found in Connecticut, Delaware, Maryland, New Jersey, New York, and Pennsylvania. A&P's liquor stores, known as...

 heir Huntington Hartford

Huntington Hartford

George Huntington Hartford II was an American businessman, philanthropist, filmmaker, and art collector. The heir to the A&P supermarket fortune, he owned Paradise Island in the Bahamas, and had numerous other business and real estate interests over his lifetime including the Oil Shale Corporation...

, and originally focused on extracting oil from oil shale

Oil shale

Oil shale, an organic-rich fine-grained sedimentary rock, contains significant amounts of kerogen from which liquid hydrocarbons called shale oil can be produced...

 and developing alternative energy

Alternative energy

Alternative energy is an umbrella term that refers to any source of usable energy intended to replace fuel sources without the undesired consequences of the replaced fuels....

 sources.

Oil shale operations

In 1964 Tosco, Standard Oil of Ohio

Standard Oil of Ohio

Standard Oil of Ohio or Sohio was an American oil company that was acquired by British Petroleum, now called BP.It was one of the successor companies to Standard Oil after the antitrust breakup in 1911. Standard Oil of Ohio was the original Standard Oil company founded by John D. Rockefeller. It...

, and Cleveland Cliffs Iron Company formed Colony Development, a joint venture company to develop the Colony Oil Shale Project in Colorado

Colorado

Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...

 and to commercialize the TOSCO II technology

TOSCO II process

The TOSCO II process is an above ground retorting technology for shale oil extraction, which uses fine particles of oil shale that are heated in a rotating kiln. The particularity of this process is that it use hot ceramic balls for the heat transfer between the retort and a heater...

. In 1969, ARCO

ARCO

Atlantic Richfield Company is an oil company with operations in the United States as well as in Indonesia, the North Sea, and the South China Sea. It has more than 1,300 gas stations in the western part of the United States. ARCO was originally formed by the merger of East Coast-based Atlantic...

 joined the project. The project was ended in April 1972.

Expansion

In 1976 the company name was shortened to Tosco after the company acquired the Avon Refinery in Concord, California

Concord, California

Concord is the largest city in Contra Costa County, California, USA. At the 2010 census, the city had a population of 122,067. Originally founded in 1869 as the community of Todos Santos by Salvio Pacheco, the name was changed to Concord within months...

, and other west coast facilities from Phillips Petroleum

Phillips Petroleum

Phillips Petroleum Company was founded in 1917 by L.E. Phillips and Frank Phillips, of Bartlesville, Oklahoma. Their younger brother Waite Phillips was the benefactor of Philmont Scout Ranch....

, making it a major player in petroleum refining. The company continued its efforts in oil shale extraction until May 2, 1982 when Exxon

Exxon

Exxon is a chain of gas stations as well as a brand of motor fuel and related products by ExxonMobil. From 1972 to 1999, Exxon was the corporate name of the company previously known as Standard Oil Company of New Jersey or Jersey Standard....

 (which had bought Atlantic Richfield's 60% share in the project in 1980) pulled out of the Colony Project joint venture, leaving Tosco unable to keep the venture viable in spite of a $1.1 million loan guarantee from the U.S. government. Exxon claimed the project's projected $6 billion price tag made the project no longer feasible, but Exxon was required to purchase Tosco's 40% share in the project as a result of their withdrawal.

Reorganization

A major company reorganization followed in 1983. Several takeover bids during the 1980s failed to materialize, and another major reorganization took place in 1991 with the company moving its headquarters to Stamford, Connecticut

Stamford, Connecticut

Stamford is a city in Fairfield County, Connecticut, United States. According to the 2010 census, the population of the city is 122,643, making it the fourth largest city in the state and the eighth largest city in New England...

.

Acquisitions

In 1996, Tosco acquired the Circle K

Circle K

Circle K is an international chain of convenience stores, founded in 1951, in El Paso, Texas, United States. It is owned and operated by the Canadian-based Alimentation Couche-Tard.-Overview:...

 chain of convenience store

Convenience store

A convenience store, corner store, corner shop, commonly called a bodega in Spanish-speaking areas of the United States, is a small store or shop in a built up area that stocks a range of everyday items such as groceries, toiletries, alcoholic and soft drinks, and may also offer money order and...

s. In 1997, Tosco bought the rights to the Union 76

Union 76

76 is a chain of gas stations located within the United States. The 76 brand is owned by ConocoPhillips. Union Oil Company of California, dba Unocal, the original owner and creator of the Union 76 brand merged with Chevron Corporation in 2005.In 1997, Unocal sold its western United States refining...

 brand of gas stations and the western United States refining and marketing operations from Unocal.

Mergers

Tosco merged with Phillips Petroleum in 2001.
Phillips merged with Conoco in 2002 to become ConocoPhillips

ConocoPhillips

ConocoPhillips Company is an American multinational energy corporation with its headquarters located in the Energy Corridor district of Houston, Texas in the United States...

, who spun off the Circle K stores to Canadian-based Alimentation Couche-Tard

Alimentation Couche-Tard

Alimentation Couche-Tard Inc. or simply Couche-Tard is one of the largest company-owned convenience store operators in the world with up to 6,000 stores across Canada, the United States, Mexico, Japan, China, Indonesia and Guam....

.

1999 refinery accident

On February 23, 1999, four workers at the Avon Refinery in Concord were burned to death after they tried to replace a leaky oil pipe. The San Francisco Chronicle reported that one Tosco employee, Anthony Creggett, claimed shortly after the fire that plant managers had refused a request by four workers to shut down the high-temperature distillation tower during the repairs on the pipe.