# Relationship history for MSHA mine 3607323

Current hierarchy: **Graham Merwin → Graham Brothers Lumber Company Inc → Smith Property**

- 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:** Graham Brothers Lumber Company Inc → Smith Property; 1982-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Graham Merwin → Smith Property; 1982-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Graham Merwin → Graham Brothers Lumber Company Inc; 1982-06-01 to current/open; source msha-controller-operator-history