Its service territory covers most of Oklahoma, much of the eastern half of Kansas, and several disparate portions of Texas.

[citation needed] Its largest natural gas distribution markets by customer count are Oklahoma City and Tulsa, Oklahoma; Kansas City, Wichita and Topeka, Kansas; and Austin and El Paso, Texas.

One Gas serves residential, commercial, industrial, transportation and wholesale customers in all three states.

It is the largest natural gas distributor in Oklahoma and Kansas, and the third-largest in Texas, in terms of customer count.

[citation needed] One Gas was founded in February 2014 when Oneok spun off its distribution subsidiaries.