On 1 January 1901, the northwestern district of Grong (population: 1,046) was separated to form the new Høylandet Municipality.

The official blazon is "Argent, three triangles vert in pale" (Norwegian: I sølv tre grønne trekanter, 1-1-1).

The green triangles symbolize spruce trees (Norwegian: gran) which dominate almost 40% of the municipal areas.

This makes them canting arms since the name of the municipality is supposedly derived from Granungar which means spruce.

The number three symbolizes the three main villages in the municipality: Harran, Bergsmoen, and Medjå.

The municipal council (Kommunestyre) of Grong is made up of 17 representatives that are elected to four year terms.

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

Here is a list of people who have held this position:[32][33][34] The European route E6 highway follows the river Namsen across the municipality, as does the Nordland Line.