EXHIBIT 21
LIST OF SUBSIDIARIES
Subsidiary Name	Location of Incorporation or Organization
SEECO, Inc.	Arkansas
Southwestern Energy Production Company	Arkansas
Diamond “M” Production Company	Delaware
DeSoto Drilling, Inc.	Arkansas
DeSoto Sand, L.L.C.	Arkansas
Southwestern Midstream Services Company	Arkansas
Southwestern Energy Services Company	Arkansas
DeSoto Gathering Company, L.L.C.	Arkansas
A. W. Realty Company	Arkansas
Angelina Gathering Company, L.L.C.	Texas
Southwestern Field Services, L.L.C.	Arkansas
SWN International, L.L.C.	Delaware
SWN Producer Services, L.L.C.	Arkansas
SWN Resources Canada, Inc.	New Brunswick, Canada