# Relationship history for MSHA mine 0202612

Current hierarchy: **Taiheiyo Cement Corp → CPC Southwest Materials Inc → PORTABLE CRUSHER 05**

- 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:** Ashland Inc → PORTABLE CRUSHER 05; 1987-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tanner Companies → PORTABLE CRUSHER 05; 1994-01-01 to 1994-05-15; source msha-controller-operator-history
- **controller_controls_operator:** Ashland Inc → Tanner Companies; 1994-01-01 to 1994-05-15; source msha-controller-operator-history
- **operator_operates_mine:** Tucson Rock & Sand Inc → PORTABLE CRUSHER 05; 1994-05-16 to 1997-06-06; source msha-controller-operator-history
- **controller_controls_mine:** Lloyd B  Fry et al → PORTABLE CRUSHER 05; 1994-05-16 to 1997-06-06; source msha-controller-operator-history
- **controller_controls_operator:** Lloyd B  Fry et al → Tucson Rock & Sand Inc; 1994-05-16 to 1997-06-06; source msha-controller-operator-history
- **operator_operates_mine:** Tucson Ready Mix Inc → PORTABLE CRUSHER 05; 1997-06-07 to 2005-08-28; source msha-controller-operator-history
- **controller_controls_mine:** RMC Group PLC → PORTABLE CRUSHER 05; 1997-06-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** RMC Group PLC → Tucson Ready Mix Inc; 1997-06-07 to 2005-08-28; source msha-controller-operator-history
- **operator_operates_mine:** CPC Southwest Materials Inc → PORTABLE CRUSHER 05; 2005-08-29 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Taiheiyo Cement Corp → PORTABLE CRUSHER 05; 2005-08-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Taiheiyo Cement Corp → CPC Southwest Materials Inc; 2005-08-29 to current/open; source msha-controller-operator-history