# Relationship history for MSHA mine 4604316

Current hierarchy: **Smith Michael O → Module Home Service Inc → Bickmore Auger**

- 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:** M H Company Inc → Bickmore Auger; 1974-01-01 to 1975-04-29; source msha-controller-operator-history
- **controller_controls_mine:** M H Co Inc → Bickmore Auger; 1974-01-01 to 1975-04-29; source msha-controller-operator-history
- **controller_controls_operator:** M H Co Inc → M H Company Inc; 1974-01-01 to 1975-04-29; source msha-controller-operator-history
- **operator_operates_mine:** Module Home Service Inc → Bickmore Auger; 1975-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Smith Michael O → Bickmore Auger; 1975-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Smith Michael O → Module Home Service Inc; 1975-04-30 to current/open; source msha-controller-operator-history