# Relationship history for MSHA mine 0504523

Current hierarchy: **Baca County-CO → Baca County → DISTRICT #1 SCREEN 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

- **controller_controls_mine:** Baca County-CO → DISTRICT #1 SCREEN PLANT; 1992-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Baca County → DISTRICT #1 SCREEN PLANT; 1993-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Baca County-CO → Baca County; 1993-07-01 to current/open; source msha-controller-operator-history