Union Island is a island located in San Joaquin County, California. It appears on the Union Island USGS 7.5-minute topographic quadrangle. The nearest populated place is Mountain House, approximately 6.3 miles to the SW.
San Joaquin County · California
Union Island is a island located in San Joaquin County, California. It appears on the Union Island USGS 7.5-minute topographic quadrangle. The nearest populated place is Mountain House, approximately 6.3 miles to the SW.