# Relationship history for MSHA mine 4701758

Current hierarchy: **Tony  Thier → BARD Materials → Portable Crushing 2**

- 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:** Kowalski-Kieler Inc → Portable Crushing 2; 1950-01-01 to 2018-01-23; source msha-controller-operator-history
- **controller_controls_mine:** Dennis J  Thier et al → Portable Crushing 2; 1950-01-01 to 2014-03-02; source msha-controller-operator-history
- **controller_controls_mine:** Jack L  Kieler et al → Portable Crushing 2; 1950-01-01 to 2009-05-05; source msha-controller-operator-history
- **controller_controls_operator:** Jack L  Kieler et al → Kowalski-Kieler Inc; 1950-01-01 to 2009-05-05; source msha-controller-operator-history
- **controller_controls_operator:** Wilfred  Udelhofen et al → Kowalski-Kieler Inc; 1950-01-01 to 2009-05-05; source msha-controller-operator-history
- **controller_controls_mine:** Dennis J  Thier et al → Portable Crushing 2; 2009-05-06 to 2014-03-02; source msha-controller-operator-history
- **controller_controls_operator:** Dennis J  Thier et al → Kowalski-Kieler Inc; 2009-05-06 to 2014-03-02; source msha-controller-operator-history
- **controller_controls_mine:** Tony  Thier → Portable Crushing 2; 2014-03-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tony  Thier → Kowalski-Kieler Inc; 2014-03-03 to 2018-01-23; source msha-controller-operator-history
- **operator_operates_mine:** BARD Materials → Portable Crushing 2; 2018-01-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tony  Thier → BARD Materials; 2018-01-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dennis J  Thier et al → BARD Materials; 2018-01-24 to 2014-03-02; source msha-controller-operator-history