# Relationship history for MSHA mine 1202067

Current hierarchy: **Jeffrey A  Bell → Bell Aggregates & Trucking → Bell Aggregates & Trucking**

- 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:** Darwin Gravel Corp → Bell Aggregates & Trucking; 1990-04-01 to 1991-07-28; source msha-controller-operator-history
- **controller_controls_mine:** Philip R  Bird → Bell Aggregates & Trucking; 1990-04-01 to 1991-07-28; source msha-controller-operator-history
- **controller_controls_operator:** Philip R  Bird → Darwin Gravel Corp; 1990-04-01 to 1991-07-28; source msha-controller-operator-history
- **operator_operates_mine:** Bell Aggregates & Trucking → Bell Aggregates & Trucking; 1991-07-29 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jeffrey A  Bell → Bell Aggregates & Trucking; 1991-07-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jeffrey A  Bell → Bell Aggregates & Trucking; 1991-07-29 to current/open; source msha-controller-operator-history