# Relationship history for MSHA mine 2001437

Current hierarchy: **Daniel W  Holloway → Holloway Sand & Gravel Company Inc → Oakland County 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

- **operator_operates_mine:** Great Lakes Gravel Company Inc → Oakland County Pit; 1950-01-01 to 1979-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Abercrombie Roy → Oakland County Pit; 1950-01-01 to 1985-08-27; source msha-controller-operator-history
- **controller_controls_operator:** Abercrombie Roy → Great Lakes Gravel Company Inc; 1950-01-01 to 1979-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Daniel W  Holloway → Oakland County Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Holloway Sand & Gravel Company Inc → Oakland County Pit; 1979-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Daniel W  Holloway → Holloway Sand & Gravel Company Inc; 1979-10-01 to current/open; source msha-controller-operator-history