# Relationship history for MSHA mine 4703638

Current hierarchy: **Barb  Frazer; Adam  Frazer → A & B Materials → Frazer Mine**

- 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:** A & B Materials → Frazer Mine; 2012-03-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Adam  Frazer et al → Frazer Mine; 2012-03-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Adam  Frazer et al → A & B Materials; 2012-03-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Barb  Frazer et al → A & B Materials; 2012-03-16 to current/open; source msha-controller-operator-history