# Relationship history for MSHA mine 3303927

Current hierarchy: **Rawson Sonny → Mason Mining Company → Mason Mine**

- 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:** Mason Mining Company → Mason Mine; 1982-12-01 to 1986-01-16; source msha-controller-operator-history
- **controller_controls_mine:** Mason Robert → Mason Mine; 1982-12-01 to 1986-01-16; source msha-controller-operator-history
- **controller_controls_operator:** Mason Robert → Mason Mining Company; 1982-12-01 to 1986-01-16; source msha-controller-operator-history
- **operator_operates_mine:** Mason Mining Company → Mason Mine; 1986-01-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Rawson Sonny → Mason Mine; 1986-01-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rawson Sonny → Mason Mining Company; 1986-01-17 to current/open; source msha-controller-operator-history