# Relationship history for MSHA mine 4801097

Current hierarchy: **Louis B  Roberts → C R Roberts & Sons Inc → Fisherman Sand And Gravel 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:** C R Roberts & Sons Inc → Fisherman Sand And Gravel Pit; 1978-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Louis B  Roberts → Fisherman Sand And Gravel Pit; 1978-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Louis B  Roberts → C R Roberts & Sons Inc; 1978-03-09 to current/open; source msha-controller-operator-history