# Relationship history for MSHA mine 4101128

Current hierarchy: **Hanson PLC → Hanson Aggregates West Inc → BOX CANYON PLANT**

- 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:** Hanson PLC → BOX CANYON PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Panhandle Gravel West Inc → BOX CANYON PLANT; 1950-01-01 to 1988-02-29; source msha-controller-operator-history
- **controller_controls_mine:** Fu  C  Chow et al → BOX CANYON PLANT; 1950-01-01 to 1988-02-29; source msha-controller-operator-history
- **controller_controls_operator:** Fu  C  Chow et al → Panhandle Gravel West Inc; 1950-01-01 to 1988-02-29; source msha-controller-operator-history
- **controller_controls_mine:** Pioneer International Ltd → BOX CANYON PLANT; 1984-08-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Charles D  Baldwin → BOX CANYON PLANT; 1988-01-01 to 1998-02-04; source msha-controller-operator-history
- **operator_operates_mine:** Panhandle Gravel West Inc → BOX CANYON PLANT; 1988-03-01 to 1992-02-25; source msha-controller-operator-history
- **controller_controls_mine:** Alvin F Hicks → BOX CANYON PLANT; 1988-03-01 to 1992-02-25; source msha-controller-operator-history
- **controller_controls_operator:** Alvin F Hicks → Panhandle Gravel West Inc; 1988-03-01 to 1992-02-25; source msha-controller-operator-history
- **operator_operates_mine:** Western Sand & Gravel Company Inc → BOX CANYON PLANT; 1992-02-26 to 1998-02-04; source msha-controller-operator-history
- **controller_controls_operator:** Charles D  Baldwin → Western Sand & Gravel Company Inc; 1992-02-26 to 1998-02-04; source msha-controller-operator-history
- **operator_operates_mine:** Pioneer South Central Inc → BOX CANYON PLANT; 1998-02-05 to 2000-08-03; source msha-controller-operator-history
- **controller_controls_operator:** Pioneer International Ltd → Pioneer South Central Inc; 1998-02-05 to 2000-08-03; source msha-controller-operator-history
- **operator_operates_mine:** Hanson Aggregates West Inc → BOX CANYON PLANT; 2000-08-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Hanson Aggregates West Inc; 2000-08-04 to current/open; source msha-controller-operator-history