# Relationship history for MSHA mine 3301612

Current hierarchy: **John D  Ellis → United Aggregates Inc → UNITED AGGREGATES, 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Purdy Sand & Gravel Company → UNITED AGGREGATES, INC.; 1950-01-01 to 1989-02-28; source msha-controller-operator-history
- **controller_controls_mine:** J R  Purdy → UNITED AGGREGATES, INC.; 1950-01-01 to 1989-02-28; source msha-controller-operator-history
- **controller_controls_operator:** J R  Purdy → Purdy Sand & Gravel Company; 1950-01-01 to 1989-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Sant Sand & Gravel Inc → UNITED AGGREGATES, INC.; 1989-03-01 to 1994-09-06; source msha-controller-operator-history
- **controller_controls_mine:** Keith L  Sant → UNITED AGGREGATES, INC.; 1989-03-01 to 1994-09-06; source msha-controller-operator-history
- **controller_controls_operator:** Keith L  Sant → Sant Sand & Gravel Inc; 1989-03-01 to 1994-09-06; source msha-controller-operator-history
- **operator_operates_mine:** United Aggregates Inc → UNITED AGGREGATES, INC.; 1994-09-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John D  Ellis et al → UNITED AGGREGATES, INC.; 1994-09-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John D  Ellis et al → United Aggregates Inc; 1994-09-07 to current/open; source msha-controller-operator-history