# Relationship history for MSHA mine 4502883

Current hierarchy: **Kennith  Johnson → Johnson Quality Rock → JOHNSON QUALITY ROCK**

- 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

- **controller_controls_mine:** George  Weyerhaeuser et al → JOHNSON QUALITY ROCK; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Weyerhaeuser Company → JOHNSON QUALITY ROCK; 1980-12-01 to 1985-10-14; source msha-controller-operator-history
- **controller_controls_operator:** George  Weyerhaeuser et al → Weyerhaeuser Company; 1980-12-01 to 1985-10-14; source msha-controller-operator-history
- **controller_controls_mine:** Kennith  Johnson → JOHNSON QUALITY ROCK; 1980-12-03 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Johnson Quality Rock → JOHNSON QUALITY ROCK; 1985-10-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kennith  Johnson → Johnson Quality Rock; 1985-10-15 to current/open; source msha-controller-operator-history