# Relationship history for MSHA mine 1512225

Current hierarchy: **Hill Zelma → Shevon Coal Inc → No 1**

- 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

- **controller_controls_mine:** Smith Sam B → No 1; 1975-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Rock Bottom Coal Company → No 1; 1980-02-01 to 1983-03-20; source msha-controller-operator-history
- **controller_controls_mine:** Senters Harold & Clarence Senters Et Al → No 1; 1980-02-01 to 1984-02-14; source msha-controller-operator-history
- **controller_controls_operator:** Senters Harold & Clarence Senters Et Al → Rock Bottom Coal Company; 1980-02-01 to 1983-03-20; source msha-controller-operator-history
- **operator_operates_mine:** S H & W Coals Inc → No 1; 1983-03-21 to 1984-02-14; source msha-controller-operator-history
- **controller_controls_operator:** Smith Sam B → S H & W Coals Inc; 1983-03-21 to 1984-02-14; source msha-controller-operator-history
- **operator_operates_mine:** Shevon Coal Inc → No 1; 1984-02-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hill Zelma → No 1; 1984-02-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hill Zelma → Shevon Coal Inc; 1984-02-15 to current/open; source msha-controller-operator-history