# Relationship history for MSHA mine 4103077

Current hierarchy: **Texas Industries Inc → Txi Metroplex Stone → Txi Metroplex Stone**

- 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:** Metroplex Stone Company → Txi Metroplex Stone; 1981-06-01 to 1986-02-26; source msha-controller-operator-history
- **controller_controls_mine:** General Dynamics Corp → Txi Metroplex Stone; 1981-06-01 to 1986-02-26; source msha-controller-operator-history
- **controller_controls_operator:** General Dynamics Corp → Metroplex Stone Company; 1981-06-01 to 1986-02-26; source msha-controller-operator-history
- **operator_operates_mine:** Txi Metroplex Stone → Txi Metroplex Stone; 1986-02-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Texas Industries Inc → Txi Metroplex Stone; 1986-02-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Texas Industries Inc → Txi Metroplex Stone; 1986-02-27 to current/open; source msha-controller-operator-history