# Relationship history for MSHA mine 3402138

Current hierarchy: **John R  Thompson → J.R. THOMPSON, INC. → BRIDGEMAN QUARRY**

- 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:** John R  Thompson → BRIDGEMAN QUARRY; 1980-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** J.R. THOMPSON, INC. → BRIDGEMAN QUARRY; 2013-09-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John R  Thompson → J.R. THOMPSON, INC.; 2013-09-23 to current/open; source msha-controller-operator-history