# Relationship history for MSHA mine 4103754

Current hierarchy: **MDU Resources Group Inc → Young Materials Corporation → Howell Pit**

- 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:** F M  Young → Howell Pit; 1950-01-01 to 2003-07-10; source msha-controller-operator-history
- **operator_operates_mine:** Young Materials Corporation → Howell Pit; 1992-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** F M  Young → Young Materials Corporation; 1992-11-01 to 2003-07-10; source msha-controller-operator-history
- **controller_controls_mine:** MDU Resources Group Inc → Howell Pit; 2003-07-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Young Materials Corporation; 2003-07-11 to current/open; source msha-controller-operator-history