# Relationship history for MSHA mine 1517464

Current hierarchy: **Clyde  Boyd → Chestnut Ridge Coal Company Inc → Mine No 1**

- 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

- **controller_controls_mine:** Evans Davis → Mine No 1; 1990-05-11 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** E & M Coals Inc → Mine No 1; 1993-10-01 to 1994-01-19; source msha-controller-operator-history
- **controller_controls_operator:** Evans Davis → E & M Coals Inc; 1993-10-01 to 1994-01-19; source msha-controller-operator-history
- **operator_operates_mine:** Chestnut Ridge Coal Company Inc → Mine No 1; 1994-01-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Clyde  Boyd → Mine No 1; 1994-01-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Clyde  Boyd → Chestnut Ridge Coal Company Inc; 1994-01-20 to current/open; source msha-controller-operator-history