# Relationship history for MSHA mine 4103360

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials Soutwest, LLC → NORTH BRIDGEPORT QUARRY**

- 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 → NORTH BRIDGEPORT QUARRY; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John R  Marriott et al → NORTH BRIDGEPORT QUARRY; 1979-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Marock Inc → NORTH BRIDGEPORT QUARRY; 1986-01-01 to 1990-01-30; source msha-controller-operator-history
- **controller_controls_operator:** John R  Marriott et al → Marock Inc; 1986-01-01 to 1990-01-30; source msha-controller-operator-history
- **operator_operates_mine:** Marock Inc → NORTH BRIDGEPORT QUARRY; 1990-01-31 to 1999-09-03; source msha-controller-operator-history
- **controller_controls_mine:** Connie  Spradley → NORTH BRIDGEPORT QUARRY; 1990-01-31 to 1999-09-03; source msha-controller-operator-history
- **controller_controls_operator:** Connie  Spradley → Marock Inc; 1990-01-31 to 1999-09-03; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials Of Texas Incorporated → NORTH BRIDGEPORT QUARRY; 1999-09-04 to 2006-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → NORTH BRIDGEPORT QUARRY; 1999-09-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials Of Texas Incorporated; 1999-09-04 to 2006-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials, Inc. → NORTH BRIDGEPORT QUARRY; 2006-05-01 to 2025-05-08; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials, Inc.; 2006-05-01 to 2025-05-08; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → NORTH BRIDGEPORT QUARRY; 2007-11-26 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials Soutwest, LLC → NORTH BRIDGEPORT QUARRY; 2025-05-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials Soutwest, LLC; 2025-05-09 to current/open; source msha-controller-operator-history