# Relationship history for MSHA mine 4201443

Current hierarchy: **Shumway Robert → Bob Shumway Mining → Dunn**

- 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

- **operator_operates_mine:** Atlas Minerals → Dunn; 1950-01-01 to 1989-02-19; source msha-controller-operator-history
- **controller_controls_mine:** Atlas Corp → Dunn; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Atlas Corp → Atlas Minerals; 1950-01-01 to 1989-02-19; source msha-controller-operator-history
- **controller_controls_mine:** Shumway Robert → Dunn; 1987-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Bob Shumway Mining → Dunn; 1989-02-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shumway Robert → Bob Shumway Mining; 1989-02-20 to current/open; source msha-controller-operator-history