# Relationship history for MSHA mine 0400599

Current hierarchy: **Texas Industries Inc → Pacific Custom Materials Inc → TXI-Port Costa Plant**

- 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

- **operator_operates_mine:** Port Costa Products Company → TXI-Port Costa Plant; 1950-01-01 to 1983-06-19; source msha-controller-operator-history
- **controller_controls_mine:** G W  Jamieson → TXI-Port Costa Plant; 1950-01-01 to 1983-06-19; source msha-controller-operator-history
- **controller_controls_operator:** G W  Jamieson → Port Costa Products Company; 1950-01-01 to 1983-06-19; source msha-controller-operator-history
- **operator_operates_mine:** Port Costa Materials Inc → TXI-Port Costa Plant; 1983-06-20 to 1987-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Hans-Joerg  Rohrbach et al → TXI-Port Costa Plant; 1983-06-20 to 1987-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Hans-Joerg  Rohrbach et al → Port Costa Materials Inc; 1983-06-20 to 1987-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Port Costa Materials Inc → TXI-Port Costa Plant; 1987-06-01 to 1996-01-22; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → TXI-Port Costa Plant; 1987-06-01 to 1996-01-22; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Port Costa Materials Inc; 1987-06-01 to 1996-01-22; source msha-controller-operator-history
- **operator_operates_mine:** Pacific Custom Materials Inc → TXI-Port Costa Plant; 1996-01-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Texas Industries Inc → TXI-Port Costa Plant; 1996-01-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Texas Industries Inc → Pacific Custom Materials Inc; 1996-01-23 to current/open; source msha-controller-operator-history