# Relationship history for MSHA mine 4402398

Current hierarchy: **Mary Schreiber  Cox → Custom Ltd → CUSTOM SAND & 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:** J R Parker & Company → CUSTOM SAND & GRAVEL; 1950-01-01 to 1984-08-06; source msha-controller-operator-history
- **controller_controls_mine:** Parker J Russell Jr → CUSTOM SAND & GRAVEL; 1950-01-01 to 1984-08-06; source msha-controller-operator-history
- **controller_controls_operator:** Parker J Russell Jr → J R Parker & Company; 1950-01-01 to 1984-08-06; source msha-controller-operator-history
- **operator_operates_mine:** Custom Ltd → CUSTOM SAND & GRAVEL; 1984-08-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mary Schreiber  Cox  et al → CUSTOM SAND & GRAVEL; 1984-08-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mary Schreiber  Cox  et al → Custom Ltd; 1984-08-07 to current/open; source msha-controller-operator-history