# Relationship history for MSHA mine 4502422

Current hierarchy: **Carl  De Gross → De Gross Construction Inc → Quarry 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Weyerhaeuser Company → Quarry Pit; 1950-01-01 to 1979-12-31; source msha-controller-operator-history
- **controller_controls_mine:** George  Weyerhaeuser et al → Quarry Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** George  Weyerhaeuser et al → Weyerhaeuser Company; 1950-01-01 to 1979-12-31; source msha-controller-operator-history
- **operator_operates_mine:** J E Work Inc → Quarry Pit; 1980-01-01 to 1982-09-07; source msha-controller-operator-history
- **controller_controls_mine:** Work James E → Quarry Pit; 1980-01-01 to 1982-09-07; source msha-controller-operator-history
- **controller_controls_operator:** Work James E → J E Work Inc; 1980-01-01 to 1982-09-07; source msha-controller-operator-history
- **controller_controls_mine:** Carl  De Gross → Quarry Pit; 1980-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** De Gross Construction Inc → Quarry Pit; 1982-09-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Carl  De Gross → De Gross Construction Inc; 1982-09-08 to current/open; source msha-controller-operator-history