# Relationship history for MSHA mine 1516012

Current hierarchy: **Ritchie Henry D--Mildred Bowman → Henry Ritchie Coal Company → Henry Ritchie Coal Co**

- 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:** Henry Ritchie Coal Company → Henry Ritchie Coal Co; 1987-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ritchie Henry D--Mildred Bowman Et Al → Henry Ritchie Coal Co; 1987-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ritchie Henry D--Mildred Bowman Et Al → Henry Ritchie Coal Company; 1987-04-01 to current/open; source msha-controller-operator-history