# Relationship history for MSHA mine 0404551

Current hierarchy: **Wayne  Dougherty → Panamint Mining Co & Defense Resources Co → Modoc Mine Open 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

- **controller_controls_mine:** Wayne  Dougherty → Modoc Mine Open Pit; 1981-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Panamint Mining Co & Defense Resources Co → Modoc Mine Open Pit; 1981-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wayne  Dougherty → Panamint Mining Co & Defense Resources Co; 1981-08-01 to current/open; source msha-controller-operator-history