# Relationship history for MSHA mine 1200138

Current hierarchy: **John W  Jones → John Jones → Porter Cave Quarry**

- 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:** Clayton Winders & Sons → Porter Cave Quarry; 1950-01-01 to 1983-10-12; source msha-controller-operator-history
- **controller_controls_mine:** Charles D  Winders et al → Porter Cave Quarry; 1950-01-01 to 1984-01-11; source msha-controller-operator-history
- **controller_controls_operator:** Charles D  Winders et al → Clayton Winders & Sons; 1950-01-01 to 1983-10-12; source msha-controller-operator-history
- **operator_operates_mine:** John Jones → Porter Cave Quarry; 1983-10-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John W  Jones → Porter Cave Quarry; 1983-10-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John W  Jones → John Jones; 1983-10-13 to current/open; source msha-controller-operator-history