# Relationship history for MSHA mine 1202271

Current hierarchy: **William Gene  Clifford → Clifford Aggregate Incorporated → PORTABLE #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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Jerry L  Irving → PORTABLE #2; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Irving Sand & Gravel Company Inc → PORTABLE #2; 2000-03-01 to 2022-01-13; source msha-controller-operator-history
- **controller_controls_operator:** Jerry L  Irving → Irving Sand & Gravel Company Inc; 2000-03-01 to 2022-01-13; source msha-controller-operator-history
- **operator_operates_mine:** Clifford Aggregate Incorporated → PORTABLE #2; 2022-01-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** William Gene  Clifford → PORTABLE #2; 2022-01-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William Gene  Clifford → Clifford Aggregate Incorporated; 2022-01-14 to current/open; source msha-controller-operator-history