# Relationship history for MSHA mine 3101998

Current hierarchy: **Carr James T → Northampton Materials Corp → Margarettsville Pit**

- 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:** Triangle Brick Company → Margarettsville Pit; 1950-01-01 to 1986-07-26; source msha-controller-operator-history
- **controller_controls_mine:** Roeben Company → Margarettsville Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roeben Company → Triangle Brick Company; 1950-01-01 to 1986-07-26; source msha-controller-operator-history
- **operator_operates_mine:** Northampton Materials Corp → Margarettsville Pit; 1986-07-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Carr James T → Margarettsville Pit; 1986-07-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Carr James T → Northampton Materials Corp; 1986-07-27 to current/open; source msha-controller-operator-history