# Relationship history for MSHA mine 0301716

Current hierarchy: **John M  Johnson → Johnson Coal & Machinery Corp → Shale-Co**

- 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

- **controller_controls_mine:** John M  Johnson → Shale-Co; 1984-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** B & J Coal Company → Shale-Co; 1991-04-01 to 1997-12-14; source msha-controller-operator-history
- **controller_controls_mine:** John M  Johnson et al → Shale-Co; 1991-04-01 to 1997-12-14; source msha-controller-operator-history
- **controller_controls_operator:** John M  Johnson et al → B & J Coal Company; 1991-04-01 to 1997-12-14; source msha-controller-operator-history
- **operator_operates_mine:** Johnson Coal & Machinery Corp → Shale-Co; 1997-12-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John M  Johnson → Johnson Coal & Machinery Corp; 1997-12-15 to current/open; source msha-controller-operator-history