# Relationship history for MSHA mine 3606402

Current hierarchy: **Adams Robert-Calvin & Gary → Triple A Coal Company → No 4 Vein Slope**

- 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:** Triple A Coal Company → No 4 Vein Slope; 1977-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Adams Robert-Calvin & Gary → No 4 Vein Slope; 1977-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Adams Robert-Calvin & Gary → Triple A Coal Company; 1977-05-01 to current/open; source msha-controller-operator-history