# Relationship history for MSHA mine 2003382

Current hierarchy: **Frank L  Roberts Jr → Roberts Bros. Excavating Inc. → Roberts Bros. Broadway 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:** Roberts Bros. Excavating INC → Roberts Bros. Broadway Pit; 2007-03-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Frank L  Roberts Jr → Roberts Bros. Broadway Pit; 2007-03-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Frank L  Roberts Jr → Roberts Bros. Excavating INC; 2007-03-08 to current/open; source msha-controller-operator-history