# Relationship history for MSHA mine 4608049

Current hierarchy: **Porter Johnny → Mutual Mining Inc → No 2 Surface**

- 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:** Porter Johnny → No 2 Surface; 1989-03-29 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Mutual Mining Inc → No 2 Surface; 1991-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Porter Johnny → Mutual Mining Inc; 1991-05-01 to current/open; source msha-controller-operator-history