# Relationship history for MSHA mine 2200593

Current hierarchy: **Heyward C  Green → Green Brothers Gravel Company Inc → Elton Road-18**

- 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:** John B  Green et al → Elton Road-18; 1950-01-01 to 2003-04-20; source msha-controller-operator-history
- **operator_operates_mine:** Green Brothers Gravel Company Inc → Elton Road-18; 1987-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John B  Green et al → Green Brothers Gravel Company Inc; 1987-04-01 to 2003-04-20; source msha-controller-operator-history
- **controller_controls_mine:** Heyward C  Green → Elton Road-18; 2003-04-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heyward C  Green → Green Brothers Gravel Company Inc; 2003-04-21 to current/open; source msha-controller-operator-history