# Relationship history for MSHA mine 4103455

Current hierarchy: **Arcosa, Inc → Trinity Materials Inc → Ennis 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:** B & M Sand & Gravel → Ennis Plant; 1987-04-01 to 1993-09-30; source msha-controller-operator-history
- **controller_controls_mine:** William (Danny)  Myre  et al → Ennis Plant; 1987-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William (Danny)  Myre  et al → B & M Sand & Gravel; 1987-04-01 to 1993-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Trinity Industries Inc → Ennis Plant; 1991-12-01 to 2018-10-31; source msha-controller-operator-history
- **operator_operates_mine:** Trinity Materials Inc → Ennis Plant; 1993-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Trinity Industries Inc → Trinity Materials Inc; 1993-10-01 to 2018-10-31; source msha-controller-operator-history
- **controller_controls_mine:** Arcosa, Inc → Ennis Plant; 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