# Relationship history for MSHA mine 1512813

Current hierarchy: **Blackburn Curtis & Randall → Cody Development Inc → No 1 Surface 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Flat Gap Mining Company → No 1 Surface Mine; 1981-04-01 to 1981-08-04; source msha-controller-operator-history
- **controller_controls_mine:** MAPCO Inc → No 1 Surface Mine; 1981-04-01 to 1981-08-04; source msha-controller-operator-history
- **controller_controls_operator:** MAPCO Inc → Flat Gap Mining Company; 1981-04-01 to 1981-08-04; source msha-controller-operator-history
- **operator_operates_mine:** Cody Development Inc → No 1 Surface Mine; 1981-08-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Blackburn Curtis & Randall → No 1 Surface Mine; 1981-08-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blackburn Curtis & Randall → Cody Development Inc; 1981-08-05 to current/open; source msha-controller-operator-history