# Relationship history for MSHA mine 3606577

Current hierarchy: **Johnson Don R & William J Morgan → Johnson & Morgan → Wolf Run Job**

- 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:** Johnson Don R & William J Morgan → Wolf Run Job; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Johnson & Morgan → Wolf Run Job; 1977-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Don R & William J Morgan → Johnson & Morgan; 1977-12-01 to current/open; source msha-controller-operator-history