# Relationship history for MSHA mine 1513146

Current hierarchy: **Hunt Preston & Todd Ball → Black Gold Development → No 2 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Black Gold Development → No 2 Strip; 1981-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hunt Preston & Todd Ball → No 2 Strip; 1981-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hunt Preston & Todd Ball → Black Gold Development; 1981-10-01 to current/open; source msha-controller-operator-history