Ranger was founded as the Maygill Petroleum Company Limited with the aim to develop oil leases in the Steveville, Alberta area.

In 1954, Jack Piece (1924–1991), originally of Montreal, acquired control of the company and renamed it West Maygill Gas and Oil Limited.

Simultaneously, Desilets and Weich formed Matlo Oils Limited to manage their share; Birkinshaw was also an officer of this company.

Directors of the new company were Jack M. Pierce, John W. Agnew, William D. Miller, Roy Armstrong, and Edward S. Halsey, all of Lusk, Wyoming.

At Maygill's 1954 Annual General Meeting, held of 8 March at the Royal York Hotel in Toronto, Jack M. Pierce was elected to the board of directors.

Chairman of the Board O. V. Birkinshaw also proposed to consolidate the company's 3,180,000 shares into 318,000, and put forth the new name West Maygill Gas and Oil Limited.

In October 1956, Maygill announced that it had acquired control of the Ranger Oil Company from American Leduc Petroleums Limited of New York City.

[3] Following the takeover, Jack M. Pierce, Roy Chamberlain, John W. Agnew, J. D. Mason, and Dr Peter C. Badgley were elected directors.

At the 1958 Annual General Meeting, held on Thursday 26 June in Calgary, shareholders voted unanimously to change West Maygill's name to Ranger Oil (Canada) Limited.

In 1977 Ranger began exploration in Suffield, Elmworth, Pembina West, Poco Verger, and Gold River (all in Alberta), and Gopher, Wolf, and Osbamet in British Columbia.

Subsequently, the United Kingdom passed the Continental Shelf Act 1964, which allowed for the commencement of mineral development in the North Sea.

During the bidding process, Pierce formed a relationship with a London broker named Michael Belmont who worked for the firm Cazenove.

Their relationship led to the creation of Scottish Canadian Oil Transportation Limited (SCOT), which was incorporated on 15 January 1970.

The London and Scottish Marine Oil Company Limited (LASMO) was incorporated on 23 April 1971 to allow new investors into the project.

In early January 1974 the semi-submersible drilling rig Sea Quest discovered oil in the Ranger-BP block 3/8 at a depth of 10,572 feet.

A new 36 inch pipeline, laid by Viking Piper, would connect the field to the newly constructed Sullum Voe Terminal in the Shetland Islands.

In 1985, burdened by his responsibilities with the company, Jack Pierce ceded the presidency to Gordon H. Bowman, while retaining the chairmanship.

[8] The newly elected chairman was S. Simon Reisman, who had been a chief negotiator in the 1987 Canada–United States Free Trade Agreement.

Elan, a pioneer of the steam assisted gravity drainage (SAGD) method, allowed Ranger to enter the heavy oil business.

The following day, Petrobank Energy and Resources Limited, also of Calgary, released a $1.6 billion plan to take over Ranger that was financed by Barclays plc.

"[10] In late April, Ranger filed lawsuits in New York, Alberta, Ontario, and Quebec to halt the offer from proceeding.

In May, Canadian Natural Resources Limited, under the leadership of president John G. Langille, stepped forward to act as a white knight in the face of Petrobank's hostile takeover.