# Relationship history for MSHA mine 4002539

Current hierarchy: **Mathews Herman H → Walden Mining Company Inc → Walden 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

- **controller_controls_mine:** Nunley James Earl → Walden No 1; 1950-01-01 to 1984-02-07; source msha-controller-operator-history
- **operator_operates_mine:** Nunley & Thompson Coal Company Inc → Walden No 1; 1979-06-01 to 1980-03-23; source msha-controller-operator-history
- **controller_controls_operator:** Nunley James Earl → Nunley & Thompson Coal Company Inc; 1979-06-01 to 1980-03-23; source msha-controller-operator-history
- **operator_operates_mine:** Walden Mining Company Inc → Walden No 1; 1980-03-24 to 1980-07-28; source msha-controller-operator-history
- **controller_controls_mine:** Powell Robert D → Walden No 1; 1980-03-24 to 1980-07-28; source msha-controller-operator-history
- **controller_controls_operator:** Powell Robert D → Walden Mining Company Inc; 1980-03-24 to 1980-07-28; source msha-controller-operator-history
- **operator_operates_mine:** Walden Mining Company Inc → Walden No 1; 1980-07-29 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mathews Herman H → Walden No 1; 1980-07-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mathews Herman H → Walden Mining Company Inc; 1980-07-29 to current/open; source msha-controller-operator-history