# Relationship history for MSHA mine 4607836

Current hierarchy: **Gerald W  Ramsburg; Charles R  Howdershelt → Buffalo Coal Company Inc → Kempton Job**

- 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:** Carl Del Signore Family Trust → Kempton Job; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Buffalo Coal Company Inc → Kempton Job; 1990-02-01 to 2001-03-29; source msha-controller-operator-history
- **controller_controls_operator:** Carl Del Signore Family Trust → Buffalo Coal Company Inc; 1990-02-01 to 2001-03-29; source msha-controller-operator-history
- **operator_operates_mine:** Buffalo Coal Company Inc → Kempton Job; 2001-03-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Charles R  Howdershelt  et al → Kempton Job; 2001-03-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Charles R  Howdershelt  et al → Buffalo Coal Company Inc; 2001-03-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gerald W  Ramsburg  et al → Buffalo Coal Company Inc; 2001-03-30 to current/open; source msha-controller-operator-history