# Relationship history for MSHA mine 3303644

Current hierarchy: **Laughbaum Rolland E → Central Oil & Gas Inc → D & L #3 (Strip)**

- 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:** Central Oil & Gas Inc → D & L #3 (Strip); 1977-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Laughbaum Rolland E → D & L #3 (Strip); 1977-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Laughbaum Rolland E → Central Oil & Gas Inc; 1977-08-01 to current/open; source msha-controller-operator-history