# Relationship history for MSHA mine 3603441

Current hierarchy: **Thomas K  Lampert → Newgate Devel. Corp. → West Pittsburgh 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Medusa Corp → West Pittsburgh Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Southdown Inc → West Pittsburgh Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Vanport Stone Inc → West Pittsburgh Quarry; 1950-01-01 to 1984-06-12; source msha-controller-operator-history
- **controller_controls_mine:** Vanport Stone Inc → West Pittsburgh Quarry; 1950-01-01 to 1984-06-12; source msha-controller-operator-history
- **controller_controls_operator:** Vanport Stone Inc → Vanport Stone Inc; 1950-01-01 to 1984-06-12; source msha-controller-operator-history
- **controller_controls_mine:** Kenlar Construction Supply Company Inc → West Pittsburgh Quarry; 1984-06-06 to 1987-06-18; source msha-controller-operator-history
- **operator_operates_mine:** Kenlar Construction Supply Company Inc → West Pittsburgh Quarry; 1984-06-13 to 1987-04-14; source msha-controller-operator-history
- **controller_controls_operator:** Kenlar Construction Supply Company Inc → Kenlar Construction Supply Company Inc; 1984-06-13 to 1987-04-14; source msha-controller-operator-history
- **operator_operates_mine:** C & C Vanport Limestone Plant #2 Inc → West Pittsburgh Quarry; 1987-04-15 to 1990-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Victor  Mashuda → West Pittsburgh Quarry; 1987-04-15 to 1990-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Victor  Mashuda → C & C Vanport Limestone Plant #2 Inc; 1987-04-15 to 1990-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Medusa Aggregates Company → West Pittsburgh Quarry; 1990-06-01 to 1998-05-14; source msha-controller-operator-history
- **controller_controls_operator:** Medusa Corp → Medusa Aggregates Company; 1990-06-01 to 1998-05-14; source msha-controller-operator-history
- **controller_controls_mine:** Cemex S A → West Pittsburgh Quarry; 1994-09-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Southdown Inc → West Pittsburgh Quarry; 1998-05-15 to 2001-02-27; source msha-controller-operator-history
- **controller_controls_operator:** Southdown Inc → Southdown Inc; 1998-05-15 to 2001-02-27; source msha-controller-operator-history
- **operator_operates_mine:** Cemex Inc → West Pittsburgh Quarry; 2001-02-28 to 2004-02-29; source msha-controller-operator-history
- **controller_controls_operator:** Cemex S A → Cemex Inc; 2001-02-28 to 2004-02-29; source msha-controller-operator-history
- **operator_operates_mine:** Newgate Devel. Corp. → West Pittsburgh Quarry; 2004-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thomas K  Lampert → West Pittsburgh Quarry; 2004-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas K  Lampert → Newgate Devel. Corp.; 2004-03-01 to current/open; source msha-controller-operator-history