# Relationship history for MSHA mine 1002053

Current hierarchy: **Kelley  Walker → Snake River Construction Co., Inc. → Portable Screening 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:** Snake River Construction Co., Inc. → Portable Screening Plant; 2004-05-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Kelley  Walker → Portable Screening Plant; 2004-05-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kelley  Walker → Snake River Construction Co., Inc.; 2004-05-05 to current/open; source msha-controller-operator-history