# Relationship history for MSHA mine 4607202

Current hierarchy: **Carl F  Frischkorn → Battle Ridge Companies → Area 26 Surface 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Delta Industries Inc → Area 26 Surface Mine; 1972-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Carl F  Frischkorn → Area 26 Surface Mine; 1982-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Delta Mining Inc → Area 26 Surface Mine; 1986-09-01 to 1992-02-02; source msha-controller-operator-history
- **controller_controls_operator:** Delta Industries Inc → Delta Mining Inc; 1986-09-01 to 1992-02-02; source msha-controller-operator-history
- **controller_controls_mine:** Moore Perry → Area 26 Surface Mine; 1991-07-18 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** C C Conley & Son'S Inc → Area 26 Surface Mine; 1992-02-03 to 1993-07-22; source msha-controller-operator-history
- **controller_controls_operator:** Moore Perry → C C Conley & Son'S Inc; 1992-02-03 to 1993-07-22; source msha-controller-operator-history
- **operator_operates_mine:** Battle Ridge Companies → Area 26 Surface Mine; 1993-07-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Carl F  Frischkorn → Battle Ridge Companies; 1993-07-23 to current/open; source msha-controller-operator-history