# Relationship history for MSHA mine 3303720

Current hierarchy: **Sampson Ralph → Z & H Mining Inc → Shirley Strip**

- 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:** Sampson Ralph → Shirley Strip; 1975-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Z & H Mining Inc → Shirley Strip; 1978-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sampson Ralph → Z & H Mining Inc; 1978-10-01 to current/open; source msha-controller-operator-history