During the 1960s, there were many municipal mergers across Norway due to the work of the Schei Committee.

This is likely referring to the two horn-shaped peninsulas that jut out into the river Otra at the entrance to the lake Breidflå.

[6] The municipal council (Herredsstyre) of Hornnes was made up of 21 representatives that were elected to four year terms.

The tables below show the historical composition of the council by political party.

There are also records in Rome referring to "Ornes i Odralen" (Hornnes Church is part of the Otredal prosti).