# Relationship history for MSHA mine 4604997

Current hierarchy: **Gary M  Wilson → Riverview Mining Company Inc → Riverview No 2 (Surface)**

- 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:** Riverview Mining Inc → Riverview No 2 (Surface); 1975-12-01 to 1977-03-05; source msha-controller-operator-history
- **controller_controls_mine:** Schmidt Robert E → Riverview No 2 (Surface); 1975-12-01 to 1977-03-05; source msha-controller-operator-history
- **controller_controls_operator:** Schmidt Robert E → Riverview Mining Inc; 1975-12-01 to 1977-03-05; source msha-controller-operator-history
- **operator_operates_mine:** Riverview Mining Company Inc → Riverview No 2 (Surface); 1977-03-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gary M  Wilson et al → Riverview No 2 (Surface); 1977-03-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gary M  Wilson et al → Riverview Mining Company Inc; 1977-03-06 to current/open; source msha-controller-operator-history