# Relationship history for MSHA mine 3610128

Current hierarchy: **Brenda L  Krevel → Ridge Energy Company Inc → Harmer Refuge Site**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Brenda L  Krevel → Harmer Refuge Site; 1995-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ridge Energy Company Inc → Harmer Refuge Site; 2015-01-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brenda L  Krevel → Ridge Energy Company Inc; 2015-01-13 to current/open; source msha-controller-operator-history