# Relationship history for MSHA mine 0503963

Current hierarchy: **Worley Darold E → F J Kent Pipeline Company → Smith Pit**

- 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:** F J Kent Pipeline Company → Smith Pit; 1984-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Worley Darold E → Smith Pit; 1984-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Worley Darold E → F J Kent Pipeline Company; 1984-06-01 to current/open; source msha-controller-operator-history