# Relationship history for MSHA mine 4002526

Current hierarchy: **Miracle Carl T → Happy Valley Coal Company Inc → 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:** Happy Valley Coal Company Inc → No 1 Strip; 1979-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Miracle Carl T → No 1 Strip; 1979-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Miracle Carl T → Happy Valley Coal Company Inc; 1979-05-01 to current/open; source msha-controller-operator-history