# Relationship history for MSHA mine 4002326

Current hierarchy: **Walter R  Neese et  al → Northwest Coal Company Inc → Northwest S M 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

- **controller_controls_mine:** Premier Coal Company → Northwest S M No 2; 1977-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dayton Mining Company → Northwest S M No 2; 1977-08-01 to 1978-06-11; source msha-controller-operator-history
- **controller_controls_operator:** Premier Coal Company → Dayton Mining Company; 1977-08-01 to 1978-06-11; source msha-controller-operator-history
- **operator_operates_mine:** Northwest Coal Company Inc → Northwest S M No 2; 1978-06-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Walter R  Neese et  al → Northwest S M No 2; 1978-06-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Walter R  Neese et  al → Northwest Coal Company Inc; 1978-06-12 to current/open; source msha-controller-operator-history