# Relationship history for MSHA mine 0203000

Current hierarchy: **Mining Americas Inc → Bonanza Explorations, Inc. → Copperstone 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Richard (Dick)  Merritt → Copperstone Mine; 1988-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dick Merritt Construction → Copperstone Mine; 2002-09-30 to 2005-06-07; source msha-controller-operator-history
- **controller_controls_operator:** Richard (Dick)  Merritt → Dick Merritt Construction; 2002-09-30 to 2005-06-07; source msha-controller-operator-history
- **operator_operates_mine:** Bonanza Explorations, Inc. → Copperstone Mine; 2005-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** American Bonanza Gold Corporation → Copperstone Mine; 2005-06-08 to 2014-06-26; source msha-controller-operator-history
- **controller_controls_operator:** American Bonanza Gold Corporation → Bonanza Explorations, Inc.; 2005-06-08 to 2014-06-26; source msha-controller-operator-history
- **controller_controls_mine:** Sabre Gold Mines Corp → Copperstone Mine; 2014-06-27 to 2025-02-05; source msha-controller-operator-history
- **controller_controls_operator:** Sabre Gold Mines Corp → Bonanza Explorations, Inc.; 2014-06-27 to 2025-02-05; source msha-controller-operator-history
- **controller_controls_mine:** Mining Americas Inc → Copperstone Mine; 2025-02-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mining Americas Inc → Bonanza Explorations, Inc.; 2025-02-06 to current/open; source msha-controller-operator-history