The name of the company that operated the subject gas storage field in 1998 (from IGS Special Report 59, Underground storage of natural gas in Indiana (revised), 1998).
The best source for current operator names is the Division of Oil and Gas (DOG). See their Active Operator List at < http://www.in.gov/dnr/dnroil/files/og-ActiveOperatorList.pdf >
Keller, S. J., 1998, Underground storage of natural gas in Indiana: Indiana Geological Survey, Special Report 59, 77 p.