The province of Dalarna is slightly larger than the county, as the westernmost part of Ljusdal Municipality belongs to it.

For the most part sparsely populated and with extensive tracts of wilderness, Dalarna County is almost as large as Belgium in terms of land area.

In older times, Dalarna was periodically part of the territory ruled by the governor of Västerås Castle.

The Kopparbergs län (literally Copper Mountain County) was finally created by royal decree in 1647.

The main aim of the County Administrative Board is to fulfil the goals set in national politics by the Riksdag and the Government, to coordinate the interests and promote the development of the county, to establish regional goals and safeguard the due process of law in the handling of each case.