# Relationship history for MSHA mine 1513703

Current hierarchy: **Baker Mike → Strata Coal Company 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:** Strata Coal Company Inc → No 1 Surface Mine; 1982-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Baker Mike Et Al → No 1 Surface Mine; 1982-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Baker Mike Et Al → Strata Coal Company Inc; 1982-09-01 to current/open; source msha-controller-operator-history