# Relationship history for MSHA mine 3607494

Current hierarchy: **Altmire Brothers Coal Company Inc → Double A Coal Company → Orchard Hill 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

- **controller_controls_mine:** Altmire Brothers Coal Company Inc → Orchard Hill Strip; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Double A Coal Company → Orchard Hill Strip; 1983-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Altmire Brothers Coal Company Inc → Double A Coal Company; 1983-08-01 to current/open; source msha-controller-operator-history