# Relationship history for MSHA mine 2500443

Current hierarchy: **Colas S A → Simon Contractors → Ogallala Portable Barge**

- 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:** Armour Construction Company Inc → Ogallala Portable Barge; 1950-01-01 to 1980-02-25; source msha-controller-operator-history
- **controller_controls_mine:** Calvin  Armour → Ogallala Portable Barge; 1950-01-01 to 1980-02-25; source msha-controller-operator-history
- **controller_controls_operator:** Calvin  Armour → Armour Construction Company Inc; 1950-01-01 to 1980-02-25; source msha-controller-operator-history
- **operator_operates_mine:** Ogallala Ready Mix Company → Ogallala Portable Barge; 1980-02-26 to 2000-02-22; source msha-controller-operator-history
- **controller_controls_mine:** Keith J  Peetz → Ogallala Portable Barge; 1980-02-26 to 2000-02-22; source msha-controller-operator-history
- **controller_controls_operator:** Keith J  Peetz → Ogallala Ready Mix Company; 1980-02-26 to 2000-02-22; source msha-controller-operator-history
- **controller_controls_mine:** Colas S A → Ogallala Portable Barge; 1995-01-26 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Simon Contractors → Ogallala Portable Barge; 2000-02-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Colas S A → Simon Contractors; 2000-02-23 to current/open; source msha-controller-operator-history