# Relationship history for MSHA mine 2602273

Current hierarchy: **Rory L  Tibbals; Joyce E  Johnson → Remtech L L C → ROBINSON**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Roy A  Walker → ROBINSON; 1992-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** W E S Construction Company Inc → ROBINSON; 1994-01-01 to 1995-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Roy A  Walker → W E S Construction Company Inc; 1994-01-01 to 1995-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Remtech L L C → ROBINSON; 1995-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Joyce E  Johnson et al → ROBINSON; 1995-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joyce E  Johnson et al → Remtech L L C; 1995-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rory L  Tibbals et al → Remtech L L C; 1995-09-01 to current/open; source msha-controller-operator-history