# Relationship history for MSHA mine 4105548

Current hierarchy: ** → Century Machinery Co., Inc. → Sleepy Hills Quarry**

- 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

Historical edge projection is not bundled for this mine yet.