# Relationship history for MSHA mine 1511428

Current hierarchy: **Denniston Herman & Julian → Denniston Coal Company → No 1 Prep Plant**

- 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:** Denniston Coal Company → No 1 Prep Plant; 1978-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Denniston Herman & Julian → No 1 Prep Plant; 1978-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Denniston Herman & Julian → Denniston Coal Company; 1978-07-01 to current/open; source msha-controller-operator-history