# Relationship history for MSHA mine 3607980

Current hierarchy: **Shand Roddy → Cloud Nine Coal Company → Continental Colliery**

- 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:** Joseph  Kleeman  et al → Continental Colliery; 1987-12-22 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Pac 23 Mining Company → Continental Colliery; 1988-01-01 to 1988-05-09; source msha-controller-operator-history
- **controller_controls_operator:** Joseph  Kleeman  et al → Pac 23 Mining Company; 1988-01-01 to 1988-05-09; source msha-controller-operator-history
- **operator_operates_mine:** Cloud Nine Coal Company → Continental Colliery; 1988-05-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Shand Roddy → Continental Colliery; 1988-05-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shand Roddy → Cloud Nine Coal Company; 1988-05-10 to current/open; source msha-controller-operator-history