# Relationship history for MSHA mine 1505410

Current hierarchy: **Niece Donald & Donald Morton → D & D Mining Company → No 1 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:** Morton Mining Company → No 1 Mine; 1950-01-01 to 1974-05-01; source msha-controller-operator-history
- **controller_controls_mine:** Morton Dempsey Jr → No 1 Mine; 1950-01-01 to 1974-05-01; source msha-controller-operator-history
- **controller_controls_operator:** Morton Dempsey Jr → Morton Mining Company; 1950-01-01 to 1974-05-01; source msha-controller-operator-history
- **operator_operates_mine:** D & D Mining Company → No 1 Mine; 1974-05-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Niece Donald & Donald Morton → No 1 Mine; 1974-05-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Niece Donald & Donald Morton → D & D Mining Company; 1974-05-02 to current/open; source msha-controller-operator-history