what county is el dorado, ar
El Dorado is located about 100 miles (160 km) from Little Rock. El Dorado is located at 33Â°12â²49â³N 92Â°39â²45â³W / 33.21361Â°N 92.6625Â°W / 33.21361; -92.6625 (33.213521, -92.662553). in Union County, Arkansas in the southern part of the state. Union County is the largest county in the state of Arkansas and borders the state of Louisiana.