# Relationship history for MSHA mine 2601916

Current hierarchy: **KGHM Polska Miedz S A → Robinson Nevada Mining Company → Robinson Operation**

- 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:** Alta Gold Company → Robinson Operation; 1985-04-01 to 1990-12-14; source msha-controller-operator-history
- **controller_controls_mine:** Alta Gold Company → Robinson Operation; 1985-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alta Gold Company → Alta Gold Company; 1985-04-01 to 1990-12-14; source msha-controller-operator-history
- **operator_operates_mine:** Magma Nevada Mining Company → Robinson Operation; 1990-12-15 to 1996-02-12; source msha-controller-operator-history
- **controller_controls_mine:** Magma Copper Company → Robinson Operation; 1990-12-15 to 1996-02-12; source msha-controller-operator-history
- **controller_controls_operator:** Magma Copper Company → Magma Nevada Mining Company; 1990-12-15 to 1996-02-12; source msha-controller-operator-history
- **operator_operates_mine:** Bhp Nevada Mining Company → Robinson Operation; 1996-02-13 to 2004-04-07; source msha-controller-operator-history
- **controller_controls_mine:** Broken Hill Proprietary Company Ltd → Robinson Operation; 1996-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Broken Hill Proprietary Company Ltd → Bhp Nevada Mining Company; 1996-02-13 to 2004-04-07; source msha-controller-operator-history
- **operator_operates_mine:** Robinson Nevada Mining Company → Robinson Operation; 2004-04-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Quadra Mining Ltd → Robinson Operation; 2004-04-08 to 2012-03-20; source msha-controller-operator-history
- **controller_controls_operator:** Quadra Mining Ltd → Robinson Nevada Mining Company; 2004-04-08 to 2012-03-20; source msha-controller-operator-history
- **controller_controls_mine:** KGHM Polska Miedz S A → Robinson Operation; 2012-03-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** KGHM Polska Miedz S A → Robinson Nevada Mining Company; 2012-03-21 to current/open; source msha-controller-operator-history