# Relationship history for MSHA mine 2003137

Current hierarchy: **Bruce  Cook → Cook Brothers Excavating Inc → M21 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

- **operator_operates_mine:** Cook Brothers Excavating Inc → M21 PIT; 1999-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bruce  Cook  et al → M21 PIT; 1999-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bruce  Cook  et al → Cook Brothers Excavating Inc; 1999-09-01 to current/open; source msha-controller-operator-history