# Relationship history for MSHA mine 0403029

Current hierarchy: **Dicalite Management Group LLC → Grefco Inc → Tolbert Mine**

- 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:** Grefco Inc → Tolbert Mine; 1950-01-01 to 1985-04-10; source msha-controller-operator-history
- **controller_controls_mine:** Dicalite Management Group LLC → Tolbert Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dicalite Management Group LLC → Grefco Inc; 1950-01-01 to 1985-04-10; source msha-controller-operator-history
- **operator_operates_mine:** Coastal Earthmovers Inc → Tolbert Mine; 1985-04-11 to 1987-01-22; source msha-controller-operator-history
- **controller_controls_mine:** Hauenstein Thomas A → Tolbert Mine; 1985-04-11 to 1987-01-22; source msha-controller-operator-history
- **controller_controls_operator:** Hauenstein Thomas A → Coastal Earthmovers Inc; 1985-04-11 to 1987-01-22; source msha-controller-operator-history
- **operator_operates_mine:** Grefco Inc → Tolbert Mine; 1987-01-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dicalite Management Group LLC → Grefco Inc; 1987-01-23 to current/open; source msha-controller-operator-history