# Relationship history for MSHA mine 0504974

Current hierarchy: **GCC SAB de CV → GCC Rio Grande Inc → Salt Canyon**

- 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:** GCC SAB de CV → Salt Canyon; 1994-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** GCC Rio Grande Inc → Salt Canyon; 2012-10-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** GCC SAB de CV → GCC Rio Grande Inc; 2012-10-18 to current/open; source msha-controller-operator-history