# Relationship history for MSHA mine 1510277

Current hierarchy: **Fred  Morgenstern; David  Morgenstern → S A M Coal Company Inc → No 2 Tipple**

- 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:** David  Morgenstern et al → No 2 Tipple; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Schweitzer Roy B → No 2 Tipple; 1976-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** R B S Inc → No 2 Tipple; 1977-03-01 to 1979-11-13; source msha-controller-operator-history
- **controller_controls_operator:** Schweitzer Roy B → R B S Inc; 1977-03-01 to 1979-11-13; source msha-controller-operator-history
- **operator_operates_mine:** S A M Coal Company Inc → No 2 Tipple; 1979-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David  Morgenstern et al → S A M Coal Company Inc; 1979-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Fred  Morgenstern et al → S A M Coal Company Inc; 1979-11-14 to current/open; source msha-controller-operator-history