# Relationship history for MSHA mine 4103055

Current hierarchy: **Trinity Industries Inc → Transit Mix Concrete & Materials Company → Lampasas 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

- **operator_operates_mine:** R Wilkinson Inc → Lampasas Quarry; 1981-01-01 to 1984-10-09; source msha-controller-operator-history
- **controller_controls_mine:** Wilkinson C R → Lampasas Quarry; 1981-01-01 to 1984-10-09; source msha-controller-operator-history
- **controller_controls_operator:** Wilkinson C R → R Wilkinson Inc; 1981-01-01 to 1984-10-09; source msha-controller-operator-history
- **operator_operates_mine:** Tarmac Texas Inc → Lampasas Quarry; 1984-10-10 to 1992-12-14; source msha-controller-operator-history
- **controller_controls_mine:** Tarmac Plc → Lampasas Quarry; 1984-10-10 to 1992-12-14; source msha-controller-operator-history
- **controller_controls_operator:** Tarmac Plc → Tarmac Texas Inc; 1984-10-10 to 1992-12-14; source msha-controller-operator-history
- **operator_operates_mine:** Transit Mix Concrete & Materials Company → Lampasas Quarry; 1992-12-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Trinity Industries Inc → Lampasas Quarry; 1992-12-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Trinity Industries Inc → Transit Mix Concrete & Materials Company; 1992-12-15 to current/open; source msha-controller-operator-history