# Relationship history for MSHA mine 0200001

Current hierarchy: **Salt River Pima-Maricopa Indian Community → Phoenix Cement → Clarkdale Facility**

- 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:** Phoenix Cement Company → Clarkdale Facility; 1950-01-01 to 1979-12-14; source msha-controller-operator-history
- **controller_controls_mine:** Amcord Inc → Clarkdale Facility; 1950-01-01 to 1979-12-14; source msha-controller-operator-history
- **controller_controls_operator:** Amcord Inc → Phoenix Cement Company; 1950-01-01 to 1979-12-14; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Clarkdale Facility; 1979-12-07 to 1987-05-03; source msha-controller-operator-history
- **operator_operates_mine:** Phoenix Cement Company → Clarkdale Facility; 1979-12-15 to 1987-05-03; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Phoenix Cement Company; 1979-12-15 to 1987-05-03; source msha-controller-operator-history
- **operator_operates_mine:** Phoenix Cement → Clarkdale Facility; 1987-05-04 to 2008-03-19; source msha-controller-operator-history
- **controller_controls_mine:** Salt River Pima-Maricopa Indian Community → Clarkdale Facility; 1987-05-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Salt River Pima-Maricopa Indian Community → Phoenix Cement; 1987-05-04 to 2008-03-19; source msha-controller-operator-history
- **operator_operates_mine:** Salt River Materials Group → Clarkdale Facility; 2008-03-20 to 2009-09-23; source msha-controller-operator-history
- **controller_controls_mine:** Salt River Pima-Maricopa Indian Community → Clarkdale Facility; 2008-03-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Salt River Pima-Maricopa Indian Community → Salt River Materials Group; 2008-03-20 to 2009-09-23; source msha-controller-operator-history
- **operator_operates_mine:** Phoenix Cement → Clarkdale Facility; 2009-09-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Salt River Pima-Maricopa Indian Community → Phoenix Cement; 2009-09-24 to current/open; source msha-controller-operator-history