# Relationship history for MSHA mine 2902122

Current hierarchy: **Lafarge S A → Lafarge Southwest → Portable Plant P-4**

- 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

- **controller_controls_mine:** Larry W  Corn → Portable Plant P-4; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Corn Construction Company → Portable Plant P-4; 1994-01-01 to 1999-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Larry W  Corn → Corn Construction Company; 1994-01-01 to 1999-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Portable Plant P-4; 1998-02-11 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Western Mobile New Mexico Inc → Portable Plant P-4; 1999-04-01 to 2001-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Western Mobile New Mexico Inc; 1999-04-01 to 2001-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge Southwest → Portable Plant P-4; 2002-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Portable Plant P-4; 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