# Relationship history for MSHA mine 1518736

Current hierarchy: **John  Harris → Bull Creek Coal Corp → Simpson Brch Mine Face Up**

- 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

- **controller_controls_mine:** John  Harris → Simpson Brch Mine Face Up; 1992-10-28 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Bull Creek Coal Corp → Simpson Brch Mine Face Up; 2004-03-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John  Harris → Bull Creek Coal Corp; 2004-03-23 to current/open; source msha-controller-operator-history