# Relationship history for MSHA mine 1401593

Current hierarchy: **Christopher J  Eichman → Midwest Concrete Materials → Dickinson County Sand Plant # 3**

- 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:** Robert H  Eichman → Dickinson County Sand Plant # 3; 1950-01-01 to 2025-01-31; source msha-controller-operator-history
- **controller_controls_mine:** David H  Barclay et al → Dickinson County Sand Plant # 3; 1950-01-01 to 2017-05-10; source msha-controller-operator-history
- **operator_operates_mine:** Alsop Sand Company Inc → Dickinson County Sand Plant # 3; 1996-01-01 to 2017-10-15; source msha-controller-operator-history
- **controller_controls_operator:** David H  Barclay et al → Alsop Sand Company Inc; 1996-01-01 to 2017-05-10; source msha-controller-operator-history
- **controller_controls_operator:** Dane Q  Barclay et al → Alsop Sand Company Inc; 1996-01-01 to 2017-05-10; source msha-controller-operator-history
- **controller_controls_mine:** Dane Q Barclay → Dickinson County Sand Plant # 3; 2017-05-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dane Q Barclay → Alsop Sand Company Inc; 2017-05-11 to 2017-10-15; source msha-controller-operator-history
- **operator_operates_mine:** Midwest Concrete Materials → Dickinson County Sand Plant # 3; 2017-10-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert H  Eichman → Midwest Concrete Materials; 2017-10-16 to 2025-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Christopher J  Eichman → Dickinson County Sand Plant # 3; 2025-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Christopher J  Eichman → Midwest Concrete Materials; 2025-02-01 to current/open; source msha-controller-operator-history