# Relationship history for MSHA mine 3303502

Current hierarchy: **Trace James H Jr → O-Tra Industries → Brooks No 1 Strip**

- 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:** O-Tra Industries Inc → Brooks No 1 Strip; 1976-06-22 to 1978-07-11; source msha-controller-operator-history
- **controller_controls_mine:** Owens Delbert → Brooks No 1 Strip; 1976-06-22 to 1978-07-11; source msha-controller-operator-history
- **controller_controls_operator:** Owens Delbert → O-Tra Industries Inc; 1976-06-22 to 1978-07-11; source msha-controller-operator-history
- **operator_operates_mine:** O-Tra Industries → Brooks No 1 Strip; 1978-07-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Trace James H Jr → Brooks No 1 Strip; 1978-07-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Trace James H Jr → O-Tra Industries; 1978-07-12 to current/open; source msha-controller-operator-history