# Relationship history for MSHA mine 2901258

Current hierarchy: **CRH PLC → Four Corners Materials → NM Crusher #1 (portable)**

- 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

- **operator_operates_mine:** San Juan Concrete Company → NM Crusher #1 (portable); 1950-01-01 to 1997-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Gregg K  Price → NM Crusher #1 (portable); 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gregg K  Price → San Juan Concrete Company; 1950-01-01 to 1997-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Four Corners Materials → NM Crusher #1 (portable); 1997-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → NM Crusher #1 (portable); 1998-01-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Four Corners Materials; 1998-01-05 to current/open; source msha-controller-operator-history