[2] The county was established in 1871, and was named for Dakota Territory official John W.

[3] Turner County is a part of the Sioux Falls, SD Metropolitan Statistical Area.

The terrain of Turner County consists of rolling hills, carved by gullies and drainages.

[4] The terrain slopes to the south and east; its highest point is along its west boundary line, at 1,578 ft (481 m) ASL.

In terms of ancestry, 47.7% were German, 18.4% were Norwegian, 11.3% were Danish, 9.4% were Irish, 8.5% were Dutch, and 2.7% were American.

In no national election since 1932 has the county selected the Democratic Party candidate.