# Relationship history for MSHA mine 3606303

Current hierarchy: **Adams Robert L → A A Y Coal Company → Crab Run 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:** A A Y Coal Company → Crab Run Slope; 1976-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Adams Robert L Et Al → Crab Run Slope; 1976-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Adams Robert L Et Al → A A Y Coal Company; 1976-12-01 to current/open; source msha-controller-operator-history