# Relationship history for MSHA mine 4201122

Current hierarchy: **CRH PLC → Western Rock Products → WR Portable Wash Plant # 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:** Kocjan Associates Inc → WR Portable Wash Plant # 1; 1950-01-01 to 1998-09-29; source msha-controller-operator-history
- **controller_controls_mine:** John J  Kocjan et al → WR Portable Wash Plant # 1; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John J  Kocjan et al → Kocjan Associates Inc; 1950-01-01 to 1998-09-29; source msha-controller-operator-history
- **controller_controls_operator:** Gerald P  Kocjan et al → Kocjan Associates Inc; 1950-01-01 to 1998-09-29; source msha-controller-operator-history
- **operator_operates_mine:** Hancock Materials Inc → WR Portable Wash Plant # 1; 1998-09-30 to 2007-11-18; source msha-controller-operator-history
- **controller_controls_mine:** Doyle L  Hancock → WR Portable Wash Plant # 1; 1998-09-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Doyle L  Hancock → Hancock Materials Inc; 1998-09-30 to 2007-11-18; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → WR Portable Wash Plant # 1; 2002-05-29 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → WR Portable Wash Plant # 1; 2002-05-30 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Western Rock Products → WR Portable Wash Plant # 1; 2007-11-19 to 2013-07-14; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Western Rock Products; 2007-11-19 to 2013-07-14; source msha-controller-operator-history
- **operator_operates_mine:** Staker & Parson Co. → WR Portable Wash Plant # 1; 2013-07-15 to 2014-04-20; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Staker & Parson Co.; 2013-07-15 to 2014-04-20; source msha-controller-operator-history
- **operator_operates_mine:** Western Rock Products → WR Portable Wash Plant # 1; 2014-04-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Western Rock Products; 2014-04-21 to current/open; source msha-controller-operator-history