# Relationship history for MSHA mine 1519698

Current hierarchy: **Richard J.  Corman → RJ Corman Railroad Group LLC → Frankfort Quarry**

- 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:** RJ Corman Railroad Group LLC → Frankfort Quarry; 2013-03-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Richard J.  Corman et al → Frankfort Quarry; 2013-03-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard J.  Corman et al → RJ Corman Railroad Group LLC; 2013-03-14 to current/open; source msha-controller-operator-history