# Relationship history for MSHA mine 2401467

Current hierarchy: **Revett Silver Company → Troy Mine Inc. → Troy 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Asarco Inc → Troy Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Asarco Inc → Troy Mine; 1979-01-01 to 1999-10-13; source msha-controller-operator-history
- **controller_controls_operator:** Asarco Inc → Asarco Inc; 1979-01-01 to 1999-10-13; source msha-controller-operator-history
- **operator_operates_mine:** Troy Mine Inc. → Troy Mine; 1999-10-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Revett Silver Company → Troy Mine; 1999-10-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Revett Silver Company → Troy Mine Inc.; 1999-10-14 to current/open; source msha-controller-operator-history