# Relationship history for MSHA mine 0504906

Current hierarchy: **Eric J Frei → Wild Branch Stone → Flag Sand and 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Wild Branch Stone → Flag Sand and Gravel; 2008-06-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Eric J Frei → Flag Sand and Gravel; 2008-06-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eric J Frei → Wild Branch Stone; 2008-06-13 to current/open; source msha-controller-operator-history