# Relationship history for MSHA mine 1900334

Current hierarchy: **Aggregate Industries PLC → Trimount Bituminous Products Company → Groveland Operation**

- 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:** Merrimack Paving Corp → Groveland Operation; 1950-01-01 to 1979-06-10; source msha-controller-operator-history
- **controller_controls_mine:** Reilly Eugene J → Groveland Operation; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Reilly Eugene J → Merrimack Paving Corp; 1950-01-01 to 1979-06-10; source msha-controller-operator-history
- **controller_controls_mine:** Guyott Company → Groveland Operation; 1950-01-01 to 1988-05-03; source msha-controller-operator-history
- **operator_operates_mine:** Trimount Bituminous Products Company → Groveland Operation; 1979-06-11 to 1988-05-03; source msha-controller-operator-history
- **controller_controls_operator:** Guyott Company → Trimount Bituminous Products Company; 1979-06-11 to 1988-05-03; source msha-controller-operator-history
- **operator_operates_mine:** Trimount Bituminous Products Company → Groveland Operation; 1988-05-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Aggregate Industries PLC → Groveland Operation; 1988-05-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Aggregate Industries PLC → Trimount Bituminous Products Company; 1988-05-04 to current/open; source msha-controller-operator-history