# Relationship history for MSHA mine 2900869

Current hierarchy: **Lafarge S A → Lafarge Southwest → Douglas Pit**

- 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:** Constructors Inc → Douglas Pit; 1950-01-01 to 2001-02-20; source msha-controller-operator-history
- **controller_controls_mine:** Constructors Inc (NM) → Douglas Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Constructors Inc (NM) → Constructors Inc; 1950-01-01 to 2001-02-20; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Douglas Pit; 1998-02-11 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Western Mobile New Mexico Inc → Douglas Pit; 2001-02-21 to 2002-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Western Mobile New Mexico Inc; 2001-02-21 to 2002-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Douglas Pit; 2002-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge Southwest → Douglas Pit; 2002-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge Southwest; 2002-03-01 to current/open; source msha-controller-operator-history