# Relationship history for MSHA mine 3606441

Current hierarchy: **Metz Charles → Penn Sherman Corp → West Mifflin**

- 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:** Metz Charles → West Mifflin; 1974-06-24 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Pioneer International Coal Company Inc → West Mifflin; 1977-06-01 to 1978-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Smego Raymond → West Mifflin; 1977-06-01 to 1978-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Smego Raymond → Pioneer International Coal Company Inc; 1977-06-01 to 1978-01-31; source msha-controller-operator-history
- **operator_operates_mine:** Penn Sherman Corp → West Mifflin; 1978-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Metz Charles → Penn Sherman Corp; 1978-02-01 to current/open; source msha-controller-operator-history