# Relationship history for MSHA mine 0503422

Current hierarchy: **CRH PLC → Oldcastle SW Group Inc. → Specialty Crusher**

- 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:** Siegrist Construction Company Et Al → Specialty Crusher; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Burnett Construction Company → Specialty Crusher; 1979-01-01 to 1994-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Siegrist Construction Company Et Al → Burnett Construction Company; 1979-01-01 to 1994-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Durango Construction Inc → Specialty Crusher; 1994-09-01 to 1997-08-31; source msha-controller-operator-history
- **controller_controls_mine:** David L  West  et al → Specialty Crusher; 1994-09-01 to 1997-08-31; source msha-controller-operator-history
- **controller_controls_operator:** David L  West  et al → Durango Construction Inc; 1994-09-01 to 1997-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Durango Construction → Specialty Crusher; 1997-09-01 to 2001-08-25; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Specialty Crusher; 1997-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Durango Construction; 1997-09-01 to 2001-08-25; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Specialty Crusher; 1998-01-05 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Oldcastle SW Group Inc. → Specialty Crusher; 2001-08-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Oldcastle SW Group Inc.; 2001-08-26 to current/open; source msha-controller-operator-history