# Relationship history for MSHA mine 3401172

Current hierarchy: **Comers Nooks → Comers Back-Hoe Service → Comers Sand 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Comers Back-Hoe Service → Comers Sand Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Comers Nooks → Comers Sand Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Comers Nooks → Comers Back-Hoe Service; 1979-01-01 to current/open; source msha-controller-operator-history