# Relationship history for MSHA mine 4607864

Current hierarchy: **Charles Robert B → Rock Minerals Inc → #1 Washer**

- 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:** Ted  Osborne  et al → #1 Washer; 1988-09-16 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Gary Coal Sales Inc → #1 Washer; 1990-03-01 to 1993-08-10; source msha-controller-operator-history
- **controller_controls_operator:** Ted  Osborne  et al → Gary Coal Sales Inc; 1990-03-01 to 1993-08-10; source msha-controller-operator-history
- **controller_controls_mine:** Charles Robert B → #1 Washer; 1991-01-02 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Rock Minerals Inc → #1 Washer; 1993-08-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Charles Robert B → Rock Minerals Inc; 1993-08-11 to current/open; source msha-controller-operator-history