# Relationship history for MSHA mine 4609557

Current hierarchy: **Greer Industries Inc → Greer Industries Inc → Mellott HMC300HPS/CC**

- 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

- **controller_controls_mine:** Greer Industries Inc → Mellott HMC300HPS/CC; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Greer Industries Inc → Mellott HMC300HPS/CC; 2018-08-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Greer Industries Inc → Greer Industries Inc; 2018-08-29 to current/open; source msha-controller-operator-history