# Relationship history for MSHA mine 1901001

Current hierarchy: **Town Of Windsor-Ma → Town Of Windsor → Dalton Hardwood**

- 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:** Nolan Trucking Company → Dalton Hardwood; 1985-04-01 to 1985-09-25; source msha-controller-operator-history
- **controller_controls_mine:** Nolan William F → Dalton Hardwood; 1985-04-01 to 1985-09-25; source msha-controller-operator-history
- **controller_controls_operator:** Nolan William F → Nolan Trucking Company; 1985-04-01 to 1985-09-25; source msha-controller-operator-history
- **operator_operates_mine:** Town Of Windsor → Dalton Hardwood; 1985-09-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Town Of Windsor-Ma → Dalton Hardwood; 1985-09-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Town Of Windsor-Ma → Town Of Windsor; 1985-09-26 to current/open; source msha-controller-operator-history