# Relationship history for MSHA mine 4402257

Current hierarchy: **Arlie J  Lambert; Dennis B  Sutherland → Lambert Coal Company Inc → Mine #28**

- 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:** Lambert Coal Company Inc → Mine #28; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Arlie J  Lambert et al → Mine #28; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Arlie J  Lambert et al → Lambert Coal Company Inc; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dennis B  Sutherland et al → Lambert Coal Company Inc; 1950-01-01 to current/open; source msha-controller-operator-history