# Relationship history for MSHA mine 1519661

Current hierarchy: **John  DeLuca; Robert  Altenbach → SMT Operating Company, LLC → Flag Ridge**

- 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:** SMT Operating Company, LLC → Flag Ridge; 2012-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John  DeLuca et al → Flag Ridge; 2012-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John  DeLuca et al → SMT Operating Company, LLC; 2012-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Altenbach et al → SMT Operating Company, LLC; 2012-05-01 to current/open; source msha-controller-operator-history