# Relationship history for MSHA mine 3608028

Current hierarchy: **Brentzel Cathy → Penn Balt Inc → Penn-Balt No 1 Mine**

- 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

- **operator_operates_mine:** Penn Balt Inc → Penn-Balt No 1 Mine; 1988-07-01 to 1989-07-16; source msha-controller-operator-history
- **controller_controls_mine:** Umbel Jeffrey M → Penn-Balt No 1 Mine; 1988-07-01 to 1991-12-22; source msha-controller-operator-history
- **controller_controls_operator:** Umbel Jeffrey M → Penn Balt Inc; 1988-07-01 to 1989-07-16; source msha-controller-operator-history
- **operator_operates_mine:** Cherry Valley Industries Inc → Penn-Balt No 1 Mine; 1989-07-17 to 1991-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Cymbor Robert M → Penn-Balt No 1 Mine; 1989-07-17 to 1991-11-15; source msha-controller-operator-history
- **controller_controls_operator:** Cymbor Robert M → Cherry Valley Industries Inc; 1989-07-17 to 1991-11-15; source msha-controller-operator-history
- **operator_operates_mine:** Penn Balt Inc → Penn-Balt No 1 Mine; 1991-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Brentzel Cathy → Penn-Balt No 1 Mine; 1991-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brentzel Cathy → Penn Balt Inc; 1991-11-16 to current/open; source msha-controller-operator-history