It was created on 18 December 2003 by splitting away the western districts of the former Toba Samosir Regency.

The regency covers a land area of 1,444.25 square kilometres, including the whole of Samosir Island in the inland sea of Lake Toba.

[1] Its administrative seat is the town of Pangururan on the west coast of Samosir Island.

However, a small part of Pangururan District (the two villages of Desa Tanjung Bunga and kelurahan Siogung Ogung, with a combined area of 10.50 km2 and a population of 3,222 at the 2020 Census[3]) lies on the 'mainland', cut off from the rest of the district by the canal.

[4] A geopark worth Rp20 billion ($2.2 million) is expected to be created - beginning in mid-2012 - in cooperation with the Agency for the Assessment and Application of Technology (BPPT).