# Relationship history for MSHA mine 1512790

Current hierarchy: **Triplett Michael D → Smokey Bottom Coal Company Inc → No 1 Mine**

- 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:** Curtis  Francis → No 1 Mine; 1971-11-06 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Big Hill Coal Company → No 1 Mine; 1981-03-01 to 1981-12-28; source msha-controller-operator-history
- **controller_controls_operator:** Curtis  Francis → Big Hill Coal Company; 1981-03-01 to 1981-12-28; source msha-controller-operator-history
- **operator_operates_mine:** B J Coal Company → No 1 Mine; 1981-12-29 to 1982-04-12; source msha-controller-operator-history
- **controller_controls_mine:** Cooper John H → No 1 Mine; 1981-12-29 to 1982-04-12; source msha-controller-operator-history
- **controller_controls_operator:** Cooper John H → B J Coal Company; 1981-12-29 to 1982-04-12; source msha-controller-operator-history
- **operator_operates_mine:** Smokey Bottom Coal Company Inc → No 1 Mine; 1982-04-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Triplett Michael D → No 1 Mine; 1982-04-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Triplett Michael D → Smokey Bottom Coal Company Inc; 1982-04-13 to current/open; source msha-controller-operator-history