# Relationship history for MSHA mine 3610235

Current hierarchy: **Michael D  Austin → AUSTIN EXCAVATING & PAVING, INC. → ATCHISON SAND & GRAVEL**

- 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:** Michael D  Austin → ATCHISON SAND & GRAVEL; 2014-10-30 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** AUSTIN EXCAVATING & PAVING, INC. → ATCHISON SAND & GRAVEL; 2018-04-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael D  Austin → AUSTIN EXCAVATING & PAVING, INC.; 2018-04-13 to current/open; source msha-controller-operator-history