# Relationship history for MSHA mine 0503858

Current hierarchy: **Eric J Frei → Flag Resources Inc → FLAG 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

- **controller_controls_mine:** Albert R  Frei → FLAG SAND & GRAVEL; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Albert Frei & Sons Inc → FLAG SAND & GRAVEL; 1983-06-01 to 1991-06-19; source msha-controller-operator-history
- **controller_controls_operator:** Albert R  Frei → Albert Frei & Sons Inc; 1983-06-01 to 1991-06-19; source msha-controller-operator-history
- **operator_operates_mine:** Flag Resources Inc → FLAG SAND & GRAVEL; 1991-06-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Fred  Frei → FLAG SAND & GRAVEL; 1991-06-20 to 2025-05-12; source msha-controller-operator-history
- **controller_controls_operator:** Fred  Frei → Flag Resources Inc; 1991-06-20 to 2025-05-12; source msha-controller-operator-history
- **controller_controls_mine:** Eric J Frei → FLAG SAND & GRAVEL; 2025-05-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eric J Frei → Flag Resources Inc; 2025-05-13 to current/open; source msha-controller-operator-history