# Mallard Slough

> tributary to the Elk River in Grays Harbor County, Washington state, United States of America

**Wikidata**: [Q99529359](https://www.wikidata.org/wiki/Q99529359)  
**Source**: https://4ort.xyz/entity/mallard-slough-q99529359


## References

1. Geographic Names Information System
2. OpenStreetMap
3. National Hydrography Dataset
4. GeoNames
5. National Elevation Dataset