# Relationship history for MSHA mine 5001751

Current hierarchy: **Albert E  Schafer → Afognak Construction & Excavating, Inc. → Rock Grizzly**

- 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:** Albert E  Schafer → Rock Grizzly; 2001-10-15 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Afognak Construction & Excavating, Inc. → Rock Grizzly; 2002-08-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Albert E  Schafer → Afognak Construction & Excavating, Inc.; 2002-08-15 to current/open; source msha-controller-operator-history