# Relationship history for MSHA mine 1401441

Current hierarchy: **CRH PLC → Apac-Kansas Inc  Shears Division → Dodge City Sand Plant**

- 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:** Ashland Inc → Dodge City Sand Plant; 1950-01-01 to 2006-08-27; source msha-controller-operator-history
- **controller_controls_mine:** Kenneth L  Gladden → Dodge City Sand Plant; 1980-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Gladden Excavating Inc → Dodge City Sand Plant; 1984-05-01 to 2000-02-21; source msha-controller-operator-history
- **controller_controls_operator:** Kenneth L  Gladden → Gladden Excavating Inc; 1984-05-01 to 2000-02-21; source msha-controller-operator-history
- **operator_operates_mine:** Apac-Kansas Inc  Shears Division → Dodge City Sand Plant; 2000-02-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ashland Inc → Apac-Kansas Inc  Shears Division; 2000-02-22 to 2006-08-27; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Dodge City Sand Plant; 2006-08-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Apac-Kansas Inc  Shears Division; 2006-08-28 to current/open; source msha-controller-operator-history