# Relationship history for MSHA mine 4702178

Current hierarchy: **David  Mann → Mann Brothers Sand & Gravel Inc → Alby Pit 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** David  Mann → Alby Pit No 1; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Alby Materials Inc → Alby Pit No 1; 1950-01-01 to 1981-04-01; source msha-controller-operator-history
- **controller_controls_mine:** Alby Ronald → Alby Pit No 1; 1950-01-01 to 1981-04-01; source msha-controller-operator-history
- **controller_controls_operator:** Alby Ronald → Alby Materials Inc; 1950-01-01 to 1981-04-01; source msha-controller-operator-history
- **operator_operates_mine:** Mann Brothers Sand & Gravel Inc → Alby Pit No 1; 1981-04-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David  Mann → Mann Brothers Sand & Gravel Inc; 1981-04-02 to current/open; source msha-controller-operator-history