# Relationship history for MSHA mine 1513751

Current hierarchy: **Fitch Delbert → Fitch Coal & Sand Company Inc → No 1 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:** Fitch Coal & Sand Company Inc → No 1 Dredge; 1982-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Fitch Delbert → No 1 Dredge; 1982-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Fitch Delbert → Fitch Coal & Sand Company Inc; 1982-10-01 to current/open; source msha-controller-operator-history