# Relationship history for MSHA mine 1900282

Current hierarchy: **Douglas J  Macone → Assabet Sand & Gravel Co. Inc. → Assabet Sand & Gravel Co Inc**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Assabet Sand & Gravel Co. Inc. → Assabet Sand & Gravel Co Inc; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Charles  Greenough → Assabet Sand & Gravel Co Inc; 1950-01-01 to 2006-10-25; source msha-controller-operator-history
- **controller_controls_operator:** Charles  Greenough → Assabet Sand & Gravel Co. Inc.; 1950-01-01 to 2006-10-25; source msha-controller-operator-history
- **controller_controls_mine:** Douglas J  Macone → Assabet Sand & Gravel Co Inc; 2006-10-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Douglas J  Macone → Assabet Sand & Gravel Co. Inc.; 2006-10-26 to current/open; source msha-controller-operator-history