# Relationship history for MSHA mine 0200136

Current hierarchy: **Cyprus Amax Minerals Company → Cyprus Twin Buttes Corp → Cyprus Twin Buttes Corporation**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Anamax Mining Company → Cyprus Twin Buttes Corporation; 1950-01-01 to 1988-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Amax Arizona Inc-Anaconda Arizona Inc Et Al → Cyprus Twin Buttes Corporation; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Amax Arizona Inc-Anaconda Arizona Inc Et Al → Anamax Mining Company; 1950-01-01 to 1988-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Cyprus Twin Buttes Corp → Cyprus Twin Buttes Corporation; 1988-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cyprus Amax Minerals Company → Cyprus Twin Buttes Corporation; 1988-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cyprus Amax Minerals Company → Cyprus Twin Buttes Corp; 1988-04-01 to current/open; source msha-controller-operator-history