# Relationship history for MSHA mine 0404780

Current hierarchy: **David B  Blomgren → B & B Materials Inc → Lebec Plant**

- 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

- **controller_controls_mine:** David B  Blomgren  et al → Lebec Plant; 1984-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Channel & Basin Reclamation Inc → Lebec Plant; 1985-11-01 to 2002-09-01; source msha-controller-operator-history
- **controller_controls_operator:** David B  Blomgren  et al → Channel & Basin Reclamation Inc; 1985-11-01 to 2002-09-01; source msha-controller-operator-history
- **controller_controls_mine:** David B  Blomgren  et al → Lebec Plant; 1999-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** B & B Materials Inc → Lebec Plant; 2002-09-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David B  Blomgren  et al → B & B Materials Inc; 2002-09-02 to current/open; source msha-controller-operator-history