# Relationship history for MSHA mine 3600813

Current hierarchy: **Robert E  Murray → Canterbury Coal Company → David**

- 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:** Canterbury Coal Company → David; 1950-01-01 to 1989-03-09; source msha-controller-operator-history
- **controller_controls_mine:** Canterra Coal Inc → David; 1950-01-01 to 1989-03-09; source msha-controller-operator-history
- **controller_controls_operator:** Canterra Coal Inc → Canterbury Coal Company; 1950-01-01 to 1989-03-09; source msha-controller-operator-history
- **operator_operates_mine:** Canterbury Coal Company → David; 1989-03-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert E  Murray → David; 1989-03-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert E  Murray → Canterbury Coal Company; 1989-03-10 to current/open; source msha-controller-operator-history