In the 2011 Scottish Parliament election, Mountain stood in the Caithness, Sutherland and Ross constituency, where he finished fourth.

[4] At the 2015 United Kingdom general election he stood unsuccessfully in Inverness, Nairn, Badenoch and Strathspey.

In the 2016 Scottish Parliament election, Mountain stood as the Conservative candidate for Inverness and Nairn, coming second to Fergus Ewing.

Although he failed to win that seat, he was nevertheless elected as an additional member of the Scottish Parliament for the Highlands and Islands region.

[6] In the 2021 Scottish Parliament election, Mountain retained his seat as a regional member.