# Relationship history for MSHA mine 4801371

Current hierarchy: **CRH PLC → H-K Contractors Inc → Hakalo Quarry**

- 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:** Summit Inc → Hakalo Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Brent  Foster et al → Hakalo Quarry; 1950-01-01 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Koppers Company Inc → Hakalo Quarry; 1981-11-15 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sterling Sand & Gravel Company Of Wyoming → Hakalo Quarry; 1982-08-01 to 1982-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Koppers Company Inc → Sterling Sand & Gravel Company Of Wyoming; 1982-08-01 to 1982-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Summit Inc → Hakalo Quarry; 1983-01-01 to 1983-10-11; source msha-controller-operator-history
- **controller_controls_operator:** Summit Inc → Summit Inc; 1983-01-01 to 1983-10-11; source msha-controller-operator-history
- **operator_operates_mine:** H-K Contractors Inc → Hakalo Quarry; 1983-10-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brent  Foster et al → H-K Contractors Inc; 1983-10-12 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Hakalo Quarry; 2007-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → H-K Contractors Inc; 2007-11-16 to current/open; source msha-controller-operator-history