# Relationship history for MSHA mine 2901386

Current hierarchy: **Lafarge S A → Lafarge Southwest → Chiefton Powerscreen**

- 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:** Bassett Gravel Company → Chiefton Powerscreen; 1987-09-01 to 1988-07-20; source msha-controller-operator-history
- **controller_controls_mine:** George  Bassett → Chiefton Powerscreen; 1987-09-01 to 1988-07-20; source msha-controller-operator-history
- **controller_controls_operator:** George  Bassett → Bassett Gravel Company; 1987-09-01 to 1988-07-20; source msha-controller-operator-history
- **controller_controls_mine:** Redland Plc → Chiefton Powerscreen; 1988-06-14 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** H & R Gravel Products → Chiefton Powerscreen; 1988-07-21 to 1992-04-13; source msha-controller-operator-history
- **controller_controls_mine:** Stanley  Henson  et al → Chiefton Powerscreen; 1988-07-21 to 1992-04-13; source msha-controller-operator-history
- **controller_controls_operator:** Stanley  Henson  et al → H & R Gravel Products; 1988-07-21 to 1992-04-13; source msha-controller-operator-history
- **operator_operates_mine:** High Valley Sand & Gravel → Chiefton Powerscreen; 1992-04-14 to 1995-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Glen  Reed → Chiefton Powerscreen; 1992-04-14 to 1995-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Glen  Reed → High Valley Sand & Gravel; 1992-04-14 to 1995-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Western Mobile New Mexico Inc → Chiefton Powerscreen; 1995-06-01 to 1998-02-10; source msha-controller-operator-history
- **controller_controls_operator:** Redland Plc → Western Mobile New Mexico Inc; 1995-06-01 to 1998-02-10; source msha-controller-operator-history
- **operator_operates_mine:** Western Mobile New Mexico Inc → Chiefton Powerscreen; 1998-02-11 to 2001-12-09; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Chiefton Powerscreen; 1998-02-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Western Mobile New Mexico Inc; 1998-02-11 to 2001-12-09; source msha-controller-operator-history
- **operator_operates_mine:** Western Mobile Inc. → Chiefton Powerscreen; 2001-12-10 to 2001-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Western Mobile Inc.; 2001-12-10 to 2001-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge Southwest → Chiefton Powerscreen; 2002-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Chiefton Powerscreen; 2002-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge Southwest; 2002-01-01 to current/open; source msha-controller-operator-history