# Relationship history for MSHA mine 4607327

Current hierarchy: **Ward Kenneth J & Bert V Compton → Stonco Inc → Stonco No 1**

- 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:** Stone Branch Coal Inc → Stonco No 1; 1987-07-01 to 1990-01-04; source msha-controller-operator-history
- **controller_controls_mine:** Ramsey Leonard D → Stonco No 1; 1987-07-01 to 1990-01-04; source msha-controller-operator-history
- **controller_controls_operator:** Ramsey Leonard D → Stone Branch Coal Inc; 1987-07-01 to 1990-01-04; source msha-controller-operator-history
- **operator_operates_mine:** Stonco Inc → Stonco No 1; 1990-01-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ward Kenneth J & Bert V Compton → Stonco No 1; 1990-01-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ward Kenneth J & Bert V Compton → Stonco Inc; 1990-01-05 to current/open; source msha-controller-operator-history