# Relationship history for MSHA mine 3607554

Current hierarchy: **Wolfgang Randy M → Big Diamond Coal Company → No 1 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Big Diamond Coal Company → No 1 Vein Slope; 1984-03-01 to 1987-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Darryl  Koperna → No 1 Vein Slope; 1984-03-01 to 1987-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Darryl  Koperna → Big Diamond Coal Company; 1984-03-01 to 1987-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Big Diamond Coal Company → No 1 Vein Slope; 1987-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Wolfgang Randy M Et Al → No 1 Vein Slope; 1987-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wolfgang Randy M Et Al → Big Diamond Coal Company; 1987-10-01 to current/open; source msha-controller-operator-history