# Relationship history for MSHA mine 3900798

Current hierarchy: **Pete Lien & Sons Inc → Pete Lien & Sons Inc/Sand & Gravel Division → BLUNT 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Pete Lien & Sons Inc → BLUNT PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Central Sand & Gravel Inc → BLUNT PLANT; 1950-01-01 to 1980-04-02; source msha-controller-operator-history
- **controller_controls_mine:** Lloyd B  Everson → BLUNT PLANT; 1950-01-01 to 1980-04-02; source msha-controller-operator-history
- **controller_controls_operator:** Lloyd B  Everson → Central Sand & Gravel Inc; 1950-01-01 to 1980-04-02; source msha-controller-operator-history
- **operator_operates_mine:** Pete Lien & Sons Inc/Sand & Gravel Division → BLUNT PLANT; 1980-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pete Lien & Sons Inc → Pete Lien & Sons Inc/Sand & Gravel Division; 1980-04-03 to current/open; source msha-controller-operator-history