# Relationship history for MSHA mine 2301557

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials, Inc. → Stanberry Sand and Gravel**

- 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

- **controller_controls_mine:** Martin Marietta Materials Inc → Stanberry Sand and Gravel; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** B B'S Sand Company Inc → Stanberry Sand and Gravel; 1950-01-01 to 1988-03-15; source msha-controller-operator-history
- **controller_controls_mine:** Bill  Wilson → Stanberry Sand and Gravel; 1950-01-01 to 1988-03-15; source msha-controller-operator-history
- **controller_controls_operator:** Bill  Wilson → B B'S Sand Company Inc; 1950-01-01 to 1988-03-15; source msha-controller-operator-history
- **operator_operates_mine:** Allison Concrete Products Inc → Stanberry Sand and Gravel; 1988-03-16 to 1992-06-02; source msha-controller-operator-history
- **controller_controls_mine:** Laton  Allison → Stanberry Sand and Gravel; 1988-03-16 to 1992-06-02; source msha-controller-operator-history
- **controller_controls_operator:** Laton  Allison → Allison Concrete Products Inc; 1988-03-16 to 1992-06-02; source msha-controller-operator-history
- **operator_operates_mine:** Pierce Sand → Stanberry Sand and Gravel; 1992-06-03 to 2022-06-16; source msha-controller-operator-history
- **controller_controls_mine:** Bobby  Pierce → Stanberry Sand and Gravel; 1992-06-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bobby  Pierce → Pierce Sand; 1992-06-03 to 2022-06-16; source msha-controller-operator-history
- **controller_controls_mine:** Con-Agg Llc → Stanberry Sand and Gravel; 2001-12-28 to 2010-09-14; source msha-controller-operator-history
- **controller_controls_mine:** Summit Materials LLC → Stanberry Sand and Gravel; 2010-09-15 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Con-Agg Companies, LLC → Stanberry Sand and Gravel; 2022-06-17 to 2026-03-22; source msha-controller-operator-history
- **controller_controls_operator:** Con-Agg Llc → Con-Agg Companies, LLC; 2022-06-17 to 2010-09-14; source msha-controller-operator-history
- **controller_controls_operator:** Summit Materials LLC → Con-Agg Companies, LLC; 2022-06-17 to 2026-03-22; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials, Inc. → Stanberry Sand and Gravel; 2026-03-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials, Inc.; 2026-03-23 to current/open; source msha-controller-operator-history