# Relationship history for MSHA mine 3401326

Current hierarchy: **Hanson Ronald D → Blue Chip Stone Company → Blue Chip 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Blue Chip Stone Company → Blue Chip Mine; 1981-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hanson Ronald D → Blue Chip Mine; 1981-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson Ronald D → Blue Chip Stone Company; 1981-05-01 to current/open; source msha-controller-operator-history