| Subsidiary | Jurisdiction of Incorporation or Formation | |||||||
| Service Transport Company | Texas | |||||||
| Ada Crude Oil Company | Texas | |||||||
| Ada Mining Corporation | Texas | |||||||
| Classic Coal Corporation | Delaware | |||||||
| GulfMark Energy, Inc. | Texas | |||||||
| Adams Resources Medical Management, Inc. | Texas | |||||||
| Ada Resources, Inc. | Texas | |||||||
| Red River Vehicle Holdings LLC | Texas | |||||||
| Victoria Express Pipeline L.L.C. | Texas | |||||||
| GulfMark Terminals, LLC | Texas | |||||||
| ARE Captive, Inc. | Texas | |||||||
| Firebird Bulk Carriers, Inc. | Texas | |||||||
| Phoenix Oil, Inc. | Texas | |||||||
| GulfMark Asset Holdings, LLC | Texas | |||||||