# Relationship history for MSHA mine 4607679

Current hierarchy: **Jeffery S  Sisler → Colby Coal Company Inc → Hartman Bakerstown**

- 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:** Colby Coal Company Inc → Hartman Bakerstown; 1989-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jeffery S  Sisler → Hartman Bakerstown; 1989-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jeffery S  Sisler → Colby Coal Company Inc; 1989-05-01 to current/open; source msha-controller-operator-history