# Relationship history for MSHA mine 0404443

Current hierarchy: **Cimenteries Cbr Cementbedrijven → Mobile Sand Company → MOBILE SAND COMPANY**

- 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:** Mobile Sand Company → MOBILE SAND COMPANY; 1980-07-01 to 1983-06-24; source msha-controller-operator-history
- **controller_controls_mine:** Cimenteries Cbr Cementbedrijven → MOBILE SAND COMPANY; 1980-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cimenteries Cbr Cementbedrijven → Mobile Sand Company; 1980-07-01 to 1983-06-24; source msha-controller-operator-history
- **operator_operates_mine:** Mobile Sand Company → MOBILE SAND COMPANY; 1983-06-25 to 1985-01-14; source msha-controller-operator-history
- **controller_controls_mine:** Larry T  Laws et at → MOBILE SAND COMPANY; 1983-06-25 to 1985-01-14; source msha-controller-operator-history
- **controller_controls_operator:** Larry T  Laws et at → Mobile Sand Company; 1983-06-25 to 1985-01-14; source msha-controller-operator-history
- **operator_operates_mine:** Mobile Sand Company → MOBILE SAND COMPANY; 1985-01-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cimenteries Cbr Cementbedrijven → Mobile Sand Company; 1985-01-15 to current/open; source msha-controller-operator-history