# Relationship history for MSHA mine 2500907

Current hierarchy: **Bowman Gene → Kimball Sand & Gravel Inc → Larson Pit**

- 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:** Leah  Kembel → Larson Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bowman Gene → Larson Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Kimball Sand & Gravel Inc → Larson Pit; 1978-03-09 to 1980-09-15; source msha-controller-operator-history
- **controller_controls_operator:** Bowman Gene → Kimball Sand & Gravel Inc; 1978-03-09 to 1980-09-15; source msha-controller-operator-history
- **operator_operates_mine:** Kembel Sand & Gravel Company → Larson Pit; 1980-09-16 to 1981-06-14; source msha-controller-operator-history
- **controller_controls_operator:** Leah  Kembel → Kembel Sand & Gravel Company; 1980-09-16 to 1981-06-14; source msha-controller-operator-history
- **operator_operates_mine:** Kimball Sand & Gravel Inc → Larson Pit; 1981-06-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bowman Gene → Kimball Sand & Gravel Inc; 1981-06-15 to current/open; source msha-controller-operator-history