# Relationship history for MSHA mine 1600364

Current hierarchy: **M D  Bryant Jr → Mid State Sand & Gravel Company Inc → MID STATE DREDGE PLANT**

- 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:** Mid State Sand & Gravel Company Inc → MID STATE DREDGE PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** M D  Bryant Jr et al → MID STATE DREDGE PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** M D  Bryant Jr et al → Mid State Sand & Gravel Company Inc; 1950-01-01 to current/open; source msha-controller-operator-history