# Relationship history for MSHA mine 4003319

Current hierarchy: ** → Martin Sand & Gravel → Martin 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

Historical edge projection is not bundled for this mine yet.