# Relationship history for MSHA mine 1512879

Current hierarchy: **Nixon Dean → Tenkiller Mining Services 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

- **controller_controls_mine:** Nixon Dean → No 1 Surface Mine; 1980-06-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Baker C R → No 1 Surface Mine; 1980-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** C & C Mineral Inc → No 1 Surface Mine; 1981-05-01 to 1981-08-17; source msha-controller-operator-history
- **controller_controls_operator:** Baker C R → C & C Mineral Inc; 1981-05-01 to 1981-08-17; source msha-controller-operator-history
- **operator_operates_mine:** Tenkiller Mining Services Inc → No 1 Surface Mine; 1981-08-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Nixon Dean → Tenkiller Mining Services Inc; 1981-08-18 to current/open; source msha-controller-operator-history