# Relationship history for MSHA mine 4202006

Current hierarchy: **CRH PLC → Staker & Parson Companies → Erda**

- 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:** Garry L  Bolinder → Erda; 1984-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Bolinder Companies Inc → Erda; 1987-04-01 to 1996-06-11; source msha-controller-operator-history
- **controller_controls_operator:** Garry L  Bolinder → Bolinder Companies Inc; 1987-04-01 to 1996-06-11; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Erda; 1995-07-26 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Staker Paving & Construction Company Inc → Erda; 1996-06-12 to 2002-12-12; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Staker Paving & Construction Company Inc; 1996-06-12 to 2002-12-12; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Erda; 2002-05-30 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Staker & Parson Companies → Erda; 2002-12-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Staker & Parson Companies; 2002-12-13 to current/open; source msha-controller-operator-history