# Relationship history for MSHA mine 4607001

Current hierarchy: **William G  Skewes → Ramada Mining Inc → Mine No 4**

- 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:** William G  Skewes → Mine No 4; 1982-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lawson Charles W → Mine No 4; 1983-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** A W & L Mining Inc → Mine No 4; 1985-09-01 to 1987-12-21; source msha-controller-operator-history
- **controller_controls_operator:** Lawson Charles W → A W & L Mining Inc; 1985-09-01 to 1987-12-21; source msha-controller-operator-history
- **operator_operates_mine:** A W & L Mining Inc → Mine No 4; 1987-12-22 to 1989-01-26; source msha-controller-operator-history
- **controller_controls_mine:** Hylton Charles R → Mine No 4; 1987-12-22 to 1989-01-26; source msha-controller-operator-history
- **controller_controls_operator:** Hylton Charles R → A W & L Mining Inc; 1987-12-22 to 1989-01-26; source msha-controller-operator-history
- **operator_operates_mine:** Venture Coal Company Inc → Mine No 4; 1989-01-27 to 1990-04-19; source msha-controller-operator-history
- **controller_controls_mine:** Howerton Michael J → Mine No 4; 1989-01-27 to 1990-04-19; source msha-controller-operator-history
- **controller_controls_operator:** Howerton Michael J → Venture Coal Company Inc; 1989-01-27 to 1990-04-19; source msha-controller-operator-history
- **operator_operates_mine:** Ramada Mining Inc → Mine No 4; 1990-04-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William G  Skewes → Ramada Mining Inc; 1990-04-20 to current/open; source msha-controller-operator-history