# Relationship history for MSHA mine 3606967

Current hierarchy: **American Metals & Coal International Inc → Tanoma Mining Company Inc → Tanoma**

- 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:** Alco Standard Corp → Tanoma; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Barnes & Tucker Company → Tanoma; 1980-04-01 to 1986-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Alco Standard Corp → Barnes & Tucker Company; 1980-04-01 to 1986-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Tanoma Mining Company Inc → Tanoma; 1987-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** American Metals & Coal International Inc → Tanoma; 1987-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** American Metals & Coal International Inc → Tanoma Mining Company Inc; 1987-01-01 to current/open; source msha-controller-operator-history