# Relationship history for MSHA mine 3304228

Current hierarchy: **Craig  Beam → Ross County Gravel Company → ROSS COUNTY GRAVEL**

- 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:** Ross County Gravel Company → ROSS COUNTY GRAVEL; 1991-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Craig  Beam  et al → ROSS COUNTY GRAVEL; 1991-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Craig  Beam  et al → Ross County Gravel Company; 1991-02-01 to current/open; source msha-controller-operator-history