# Relationship history for MSHA mine 3606591

Current hierarchy: **Donofrio Robert → D D & R Coal Company → Diamond 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Donofrio Robert Et Al → Diamond Slope; 1975-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** D D & R Coal Company → Diamond Slope; 1978-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Donofrio Robert Et Al → D D & R Coal Company; 1978-01-01 to current/open; source msha-controller-operator-history