Hammer Island is a island located in Contra Costa County, California. It appears on the Clifton Court Forebay USGS 7.5-minute topographic quadrangle. The nearest populated place is Mountain House, approximately 2.4 miles to the SSE.
Contra Costa County · California
Hammer Island is a island located in Contra Costa County, California. It appears on the Clifton Court Forebay USGS 7.5-minute topographic quadrangle. The nearest populated place is Mountain House, approximately 2.4 miles to the SSE.