# Relationship history for MSHA mine 4101168

Current hierarchy: **Arcosa, Inc → Trinity Materials Inc → WACO S & G WEST**

- 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:** Waco Sand & Gravel Company Inc → WACO S & G WEST; 1950-01-01 to 1994-02-27; source msha-controller-operator-history
- **controller_controls_mine:** Larry G  Smith → WACO S & G WEST; 1950-01-01 to 1994-02-27; source msha-controller-operator-history
- **controller_controls_operator:** Larry G  Smith → Waco Sand & Gravel Company Inc; 1950-01-01 to 1994-02-27; source msha-controller-operator-history
- **controller_controls_mine:** Trinity Industries Inc → WACO S & G WEST; 1991-12-01 to 2018-10-31; source msha-controller-operator-history
- **operator_operates_mine:** Trinity Materials Inc → WACO S & G WEST; 1994-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Trinity Industries Inc → Trinity Materials Inc; 1994-02-28 to 2018-10-31; source msha-controller-operator-history
- **controller_controls_mine:** Arcosa, Inc → WACO S & G WEST; 2018-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Arcosa, Inc → Trinity Materials Inc; 2018-11-01 to current/open; source msha-controller-operator-history