# Relationship history for MSHA mine 4407422

Current hierarchy: **Jerry W  Wharton → J.W. Construction Company Inc. → Derby Strip #9**

- 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 W  Wharton → Derby Strip #9; 2018-03-06 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** IRON MOUNTAIN COLLIERIES, LLC. → Derby Strip #9; 2022-09-05 to 2023-07-05; source msha-controller-operator-history
- **controller_controls_mine:** Joseph D Harrison → Derby Strip #9; 2022-09-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joseph D Harrison → IRON MOUNTAIN COLLIERIES, LLC.; 2022-09-05 to 2023-07-05; source msha-controller-operator-history
- **operator_operates_mine:** J.W. Construction Company Inc. → Derby Strip #9; 2023-07-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jerry W  Wharton → J.W. Construction Company Inc.; 2023-07-06 to current/open; source msha-controller-operator-history