# Relationship history for MSHA mine 0500918

Current hierarchy: **Swerdfeger R M → Rajah Ventures Ltd → October**

- 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:** Mineral Reserves Group Inc → October; 1950-01-01 to 1983-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Energy Reserves Group Inc → October; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Energy Reserves Group Inc → Mineral Reserves Group Inc; 1950-01-01 to 1983-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Swerdfeger R M Et Al → October; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Rajah Ventures Ltd → October; 1983-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Swerdfeger R M Et Al → Rajah Ventures Ltd; 1983-07-01 to current/open; source msha-controller-operator-history