# Relationship history for MSHA mine 4606605

Current hierarchy: **Graybeal Carl N & Jack L Williams → W & G Construction Company Inc → No 1 Surface**

- 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:** K & T Excavation Inc → No 1 Surface; 1982-11-01 to 1984-05-17; source msha-controller-operator-history
- **controller_controls_mine:** Taylor Ron → No 1 Surface; 1982-11-01 to 1984-05-17; source msha-controller-operator-history
- **controller_controls_operator:** Taylor Ron → K & T Excavation Inc; 1982-11-01 to 1984-05-17; source msha-controller-operator-history
- **operator_operates_mine:** W & G Construction Company Inc → No 1 Surface; 1984-05-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Graybeal Carl N & Jack L Williams → No 1 Surface; 1984-05-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Graybeal Carl N & Jack L Williams → W & G Construction Company Inc; 1984-05-18 to current/open; source msha-controller-operator-history