# Relationship history for MSHA mine 0404627

Current hierarchy: **Cimenteries Cbr Cementbedrijven → Western Stone Products → Snelling Sand & Gravel**

- 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:** Triple C Products Inc → Snelling Sand & Gravel; 1983-02-01 to 1987-09-21; source msha-controller-operator-history
- **controller_controls_mine:** Carpenter Marvin → Snelling Sand & Gravel; 1983-02-01 to 1987-09-21; source msha-controller-operator-history
- **controller_controls_operator:** Carpenter Marvin → Triple C Products Inc; 1983-02-01 to 1987-09-21; source msha-controller-operator-history
- **operator_operates_mine:** Western Stone Products → Snelling Sand & Gravel; 1987-09-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cimenteries Cbr Cementbedrijven → Snelling Sand & Gravel; 1987-09-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cimenteries Cbr Cementbedrijven → Western Stone Products; 1987-09-22 to current/open; source msha-controller-operator-history