# Relationship history for MSHA mine 3606390

Current hierarchy: **Barry K  Bigger → Bigger Custom Grinding → Bcg-1**

- 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:** Specialty Materials Processing Inc → Bcg-1; 1977-04-01 to 1996-01-25; source msha-controller-operator-history
- **controller_controls_mine:** Cordeen C  Pfleegor III → Bcg-1; 1977-04-01 to 1996-01-25; source msha-controller-operator-history
- **controller_controls_operator:** Cordeen C  Pfleegor III → Specialty Materials Processing Inc; 1977-04-01 to 1996-01-25; source msha-controller-operator-history
- **operator_operates_mine:** Bigger Custom Grinding → Bcg-1; 1996-01-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Barry K  Bigger → Bcg-1; 1996-01-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Barry K  Bigger → Bigger Custom Grinding; 1996-01-26 to current/open; source msha-controller-operator-history