# Relationship history for MSHA mine 1300764

Current hierarchy: **Tony  Thier → Dyersville Ready Mix Inc → Clement 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:** B W  Carpenter  et al → Clement Sand Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dennis J  Thier et al → Clement Sand Plant; 1950-01-01 to 2014-03-02; source msha-controller-operator-history
- **operator_operates_mine:** Clemons Company → Clement Sand Plant; 1950-01-01 to 1979-09-04; source msha-controller-operator-history
- **controller_controls_mine:** Clemons Company → Clement Sand Plant; 1950-01-01 to 1979-09-04; source msha-controller-operator-history
- **controller_controls_operator:** Clemons Company → Clemons Company; 1950-01-01 to 1979-09-04; source msha-controller-operator-history
- **operator_operates_mine:** Alpha Crushed Stone Inc → Clement Sand Plant; 1979-09-05 to 1981-06-16; source msha-controller-operator-history
- **controller_controls_operator:** B W  Carpenter  et al → Alpha Crushed Stone Inc; 1979-09-05 to 1981-06-16; source msha-controller-operator-history
- **operator_operates_mine:** Dyersville Ready Mix Inc → Clement Sand Plant; 1981-06-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dennis J  Thier et al → Dyersville Ready Mix Inc; 1981-06-17 to 2014-03-02; source msha-controller-operator-history
- **controller_controls_mine:** Tony  Thier → Clement Sand Plant; 2014-03-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tony  Thier → Dyersville Ready Mix Inc; 2014-03-03 to current/open; source msha-controller-operator-history