# Relationship history for MSHA mine 2002022

Current hierarchy: **Melvin J  Bischer → Bischer Ready Mix Incorporated → Bad Axe 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Wagner Ready Mix → Bad Axe Pit; 1950-01-01 to 1993-03-31; source msha-controller-operator-history
- **controller_controls_mine:** James  Tanton → Bad Axe Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James  Tanton → Wagner Ready Mix; 1950-01-01 to 1993-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Bischer Ready Mix Incorporated → Bad Axe Pit; 1993-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Melvin J  Bischer → Bad Axe Pit; 1993-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Melvin J  Bischer → Bischer Ready Mix Incorporated; 1993-04-01 to current/open; source msha-controller-operator-history