# Relationship history for MSHA mine 4606990

Current hierarchy: **Gabbert Samuel W Sr → Alum Creek Sand Company → Coal River Dredge**

- 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:** Alum Creek Sand Company → Coal River Dredge; 1985-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gabbert Samuel W Sr → Coal River Dredge; 1985-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gabbert Samuel W Sr → Alum Creek Sand Company; 1985-08-01 to current/open; source msha-controller-operator-history