# Relationship history for MSHA mine 1508750

Current hierarchy: **Davenport Tracy → Cumberland Strip & Auger Inc → Surface Mine No 2**

- 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:** Cumberland Strip & Auger Inc → Surface Mine No 2; 1975-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Davenport Tracy → Surface Mine No 2; 1975-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Davenport Tracy → Cumberland Strip & Auger Inc; 1975-01-01 to current/open; source msha-controller-operator-history