# Relationship history for MSHA mine 4602900

Current hierarchy: **Alperin Norman → Birch River Coal Inc → Mine No 1**

- 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:** R & W Coal Company → Mine No 1; 1950-01-01 to 1975-05-07; source msha-controller-operator-history
- **controller_controls_mine:** Roberts Harold → Mine No 1; 1950-01-01 to 1975-05-07; source msha-controller-operator-history
- **controller_controls_operator:** Roberts Harold → R & W Coal Company; 1950-01-01 to 1975-05-07; source msha-controller-operator-history
- **controller_controls_mine:** Turner J Preston → Mine No 1; 1975-02-28 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hughes Run Coal Company → Mine No 1; 1975-05-08 to 1979-04-17; source msha-controller-operator-history
- **controller_controls_operator:** Turner J Preston → Hughes Run Coal Company; 1975-05-08 to 1979-04-17; source msha-controller-operator-history
- **operator_operates_mine:** Birch River Coal Inc → Mine No 1; 1979-04-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Alperin Norman → Mine No 1; 1979-04-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alperin Norman → Birch River Coal Inc; 1979-04-18 to current/open; source msha-controller-operator-history