# Relationship history for MSHA mine 3606996

Current hierarchy: **Primary Coal Inc → Evergreen Coal Inc → Sandpatch Siding**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** C M & J Coal Inc → Sandpatch Siding; 1980-06-01 to 1981-12-17; source msha-controller-operator-history
- **controller_controls_mine:** Rose C Edward → Sandpatch Siding; 1980-06-01 to 1981-12-17; source msha-controller-operator-history
- **controller_controls_operator:** Rose C Edward → C M & J Coal Inc; 1980-06-01 to 1981-12-17; source msha-controller-operator-history
- **controller_controls_mine:** Primary Coal Inc → Sandpatch Siding; 1981-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Evergreen Coal Inc → Sandpatch Siding; 1981-12-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Primary Coal Inc → Evergreen Coal Inc; 1981-12-18 to current/open; source msha-controller-operator-history