# Relationship history for MSHA mine 3001678

Current hierarchy: **Hart Kevin J → Hart Construction Inc → Judson 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:** Wingdale Sand & Gravel Company → Judson Mine; 1950-01-01 to 1987-07-19; source msha-controller-operator-history
- **controller_controls_mine:** Judson Wilfred S → Judson Mine; 1950-01-01 to 1987-07-19; source msha-controller-operator-history
- **controller_controls_operator:** Judson Wilfred S → Wingdale Sand & Gravel Company; 1950-01-01 to 1987-07-19; source msha-controller-operator-history
- **operator_operates_mine:** Hart Construction Inc → Judson Mine; 1987-07-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hart Kevin J → Judson Mine; 1987-07-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hart Kevin J → Hart Construction Inc; 1987-07-20 to current/open; source msha-controller-operator-history