# Relationship history for MSHA mine 4402468

Current hierarchy: **Hornsby Edward → H & R Mining Company → No 1 Strip**

- 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:** D A L Corp → No 1 Strip; 1971-09-01 to 1974-03-26; source msha-controller-operator-history
- **controller_controls_mine:** D A L Corp → No 1 Strip; 1971-09-01 to 1974-03-26; source msha-controller-operator-history
- **controller_controls_operator:** D A L Corp → D A L Corp; 1971-09-01 to 1974-03-26; source msha-controller-operator-history
- **operator_operates_mine:** H & R Mining Company → No 1 Strip; 1974-03-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hornsby Edward Et Al → No 1 Strip; 1974-03-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hornsby Edward Et Al → H & R Mining Company; 1974-03-27 to current/open; source msha-controller-operator-history