# Relationship history for MSHA mine 1200615

Current hierarchy: **Mary Ann  Nelson → A & C Products Inc → A & C Products Inc**

- 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:** A & C Enterprises Inc → A & C Products Inc; 1950-01-01 to 1992-12-08; source msha-controller-operator-history
- **controller_controls_mine:** Stephen  Clark → A & C Products Inc; 1950-01-01 to 1992-12-08; source msha-controller-operator-history
- **controller_controls_operator:** Stephen  Clark → A & C Enterprises Inc; 1950-01-01 to 1992-12-08; source msha-controller-operator-history
- **operator_operates_mine:** A & C Products Inc → A & C Products Inc; 1992-12-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mary Ann  Nelson → A & C Products Inc; 1992-12-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mary Ann  Nelson → A & C Products Inc; 1992-12-09 to current/open; source msha-controller-operator-history