1973
Pennsylvania's three districts, headquartered in Pittsburgh, Uniontown and York, serve 302,355 residential customers, 28,138 commercial and 378 industrial.

1977
A Charleroi, Pa. serviceman, honored for life-saving use of approved resuscitation methods, is the first Columbia winner of the National Safety Council's President's Medal.

1978
The nation's Natural Gas Policy Act stimulates renewed natural gas exploration and drilling..

1979
Company's supply of natural gas improves to the point where the Public Utility Commission grants its request to take on new residential, commercial and industrial customers.

1982
First company sign to conform to Columbia System's new graphics style is hung at Hanover, Pa. service center.

1983
Customers are asked to contribute to company-supported fuel funds to help low-income customers pay their winter heating bills.

1985
Pricing is deregulated on natural gas drilled since 1977.

1985
Company continues to add new customers-year's end shows 305,568 residential, 30,431 commercial and 295 industrial customers served by Columbia Gas of Pennsylvania.

1985
J.W. Partridge Jr. is elected vice president of Columbia Gas of Pennsylvania and executive offices are established in Harrisburg.

1987
Company receives citation from Pennsylvania's Energy Office for participation in the experimental critical needs weatherization program.

1988
Company introduces WarmChoice program to weatherize the homes of low-income customers and help them better manage their energy use.

1988
Offices throughout the Pittsburgh area are equipped with telecommunications devices for the deaf (TDD) to respond to inquiries from hearing- impaired customers.

1988
The gas-fueled light in the Eternal Light Peace Memorial at Gettysburg, extinguished in 1973 during the natural gas moratorium, was relighted and the memorial rededicated during the 125th anniversary of the Battle of Gettysburg, July 3,1988.

1988
Columbia begins service to new gas-fueled cogeneration system at York Hospital. Electricity and steam heating for hospital are being supplied by natural gas.

1988
Public Utility Commission rates Columbia's Customer service the best of any utility in the state and the best ever in the 10 years it has conducted its annual performance review

1989
Columbia Energy Services Corporation (CES) is begun as part of another Columbia subsidiary.

1990
Columbia's logo changes from "three stars" to "energy flame."

1991
Columbia and its wholly owned subsidiary, Columbia Transmission, file for protection under Chapter 11 of the United States Bankruptcy Code.

1993
Columbia Energy Services becomes a "stand-alone entity" and serves as Columbia's non-regulated energy-marketing subsidiary of Columbia Gas System. 

1993
Columbia Gas Transmission files its plan of reorganization with the Bankruptcy Court, a significant step forward in Columbia's Chapter 11 bankruptcy proceedings.

1994-1996
Columbia implements the Phoenix Project, which redesigns and reorganizes the company's existing organizational structures.

1995
Oliver G. Richard III becomes Chairman, president and CEO of Columbia Energy Group.

1995
Columbia and its wholly owned subsidiary, Columbia Transmission emerges from Chapter 11 protection of the United States Bankruptcy Code under the jurisdiction of the United States Bankruptcy Court for the District of Delaware.

1996
Columbia moves its corporate headquarters from Wilmington, Delaware to Reston, Virginia.

1996
The sale of Columbia Gas Development is completed, allowing Columbia to focus on exploration and production opportunities.

1996
Columbia Gas is the first natural gas utility to offer customer choice to residential and small commercial customers in CPA territory by launching its pilot Choice program.

1996
Columbia Network Services Corporation is formed.

1997
Columbia buys Alamco and PennUnion.

1998
Columbia Gas System becomes Columbia Energy Group, and Columbia's logo changes from "energy flame" to "energy burst."