# Relationship history for MSHA mine 1515621

Current hierarchy: **Robert Grover  Hunley → T & G Construction → Auger**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** T & D Coal Company → Auger; 1986-05-01 to 1987-11-02; source msha-controller-operator-history
- **controller_controls_mine:** Ted  Taylor → Auger; 1986-05-01 to 1987-11-02; source msha-controller-operator-history
- **controller_controls_operator:** Ted  Taylor → T & D Coal Company; 1986-05-01 to 1987-11-02; source msha-controller-operator-history
- **operator_operates_mine:** T & G Construction → Auger; 1987-11-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert Grover  Hunley et al → Auger; 1987-11-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert Grover  Hunley et al → T & G Construction; 1987-11-03 to current/open; source msha-controller-operator-history