# Relationship history for MSHA mine 3900708

Current hierarchy: **Pete Lien & Sons Inc → Pete Lien & Sons Inc/Sand & Gravel Division → CRESTON SAND 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

- **operator_operates_mine:** L G Everist Inc → CRESTON SAND PLANT; 1950-01-01 to 1977-08-31; source msha-controller-operator-history
- **controller_controls_mine:** L G Everist Inc → CRESTON SAND PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** L G Everist Inc → L G Everist Inc; 1950-01-01 to 1977-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Pete Lien & Sons Inc → CRESTON SAND PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Pete Lien & Sons Inc/Sand & Gravel Division → CRESTON SAND PLANT; 1977-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pete Lien & Sons Inc → Pete Lien & Sons Inc/Sand & Gravel Division; 1977-09-01 to current/open; source msha-controller-operator-history