# Relationship history for MSHA mine 1513156

Current hierarchy: **Black Al & Bob S Coleman → Gray Hawk Energy → #1 Strip**

- 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:** Gray Hawk Energy → #1 Strip; 1981-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Black Al & Bob S Coleman → #1 Strip; 1981-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Black Al & Bob S Coleman → Gray Hawk Energy; 1981-10-01 to current/open; source msha-controller-operator-history