# Relationship history for MSHA mine 0102719

Current hierarchy: **O'Barr Bill H → M D R Inc → Mine No 1**

- 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:** M D R Inc → Mine No 1; 1987-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** O'Barr Bill H → Mine No 1; 1987-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** O'Barr Bill H → M D R Inc; 1987-04-01 to current/open; source msha-controller-operator-history