Map of the 1920 Londonderry County Council election, showing all electoral areas coloured in accordance with the party that won the most votes.
The UUP won a majority of the vote in Dungiven and Coleraine, and a plurality in Magherafelt. The Nationalist party won a plurality in Kilrea.
In both areas, the majority of the vote was actually won by candidates backing the alternative constitutional position. Whilst the UUP won a plurality in Magherafelt, Irish nationalist candidates (Sinn Féin and Nationalist) won a majority of the vote. Similarly, in Kilrea unionist candidates won a majority of the vote, however the Nationalist party won more votes than any other single party.

Londonderry Corporation is coloured black
Own work
MrPenguin21