# Relationship history for MSHA mine 2000676

Current hierarchy: **Jason  Livingston; Cory  Pangborn → Bichler Concrete & Gravel → Bichler Pit**

- 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:** Bichler Gravel & Concrete Co → Bichler Pit; 1950-01-01 to 2017-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Thomas L  Brayak → Bichler Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas L  Brayak → Bichler Gravel & Concrete Co; 1950-01-01 to 2017-12-31; source msha-controller-operator-history
- **operator_operates_mine:** BICHLER CONCRETE & GRAVEL → Bichler Pit; 2018-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cory  Pangborn et al → Bichler Pit; 2018-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cory  Pangborn et al → BICHLER CONCRETE & GRAVEL; 2018-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jason  Livingston et al → BICHLER CONCRETE & GRAVEL; 2018-01-01 to current/open; source msha-controller-operator-history