# Relationship history for MSHA mine 4500974

Current hierarchy: **Miller Richard & Jack Olsen → Olsen & Miller Logging Company Inc → Mary Clark 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

- **controller_controls_mine:** Donald M  March et al → Mary Clark Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Clallam County Highway Department → Mary Clark Pit; 1950-01-01 to 1979-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Clallam County-Wa → Mary Clark Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Clallam County-Wa → Clallam County Highway Department; 1950-01-01 to 1979-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Wilder Construction Company → Mary Clark Pit; 1979-09-01 to 1980-02-25; source msha-controller-operator-history
- **controller_controls_operator:** Donald M  March et al → Wilder Construction Company; 1979-09-01 to 1980-02-25; source msha-controller-operator-history
- **operator_operates_mine:** Olsen & Miller Logging Company Inc → Mary Clark Pit; 1980-02-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Miller Richard & Jack Olsen → Mary Clark Pit; 1980-02-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Miller Richard & Jack Olsen → Olsen & Miller Logging Company Inc; 1980-02-26 to current/open; source msha-controller-operator-history