A colleague has identified major errors in the data in this paper referring to the Sami population of Jokkmokk. The errors relate to data reported in paragraph one on page 16, and paragraph one of section 6.5 on page 21. Those paragraphs report inflated estimates of the Sami population resulting from a mis-interpretation on the part of the authors of the Sami identification procedures used in the Demographic Database (DDB) at Umeå University and the Swedish Census records accessed through the North Atlantic Population Project. The authors incorrectly inferred that these data sets include validated Sami identifiers. They do not, and we apologise unreservedly to the data managers for any harm we may have caused to their reputation for ensuring data quality. A revised first sentence of the first paragraph on page 16 reads – “According to Nordin and Sköld (2014), Jokkmokk's population more than tripled during the 19th century, from 780 residents in 1790, to 1500 residents in 1840, and over 3000 residents by 1890.” A revised first paragraph in section 6.5 reads – “The impacts of hydro development on the Sami warrant some additional discussion. The data sets used in this research do not systematically identify Sami people. Previous research by two of the authors of this current paper (Nordin and Sköld, 2014) suggested a moderate increase in the total Sami population of Jokkmokk during the last quarter of the 19th century to perhaps as many as 1200 people. However, Sami went from constituting half of the population in about 1870 to less than a third by 1900. Changes in the ways in which Sami people were identified in official records after this time make further analysis problematic.” We refer readers to – Nordin, G., & Sköld, P. (2014). The complex fertility of indigenous Sami and non-reindeer-herding settlers in Jokkmokk 1815–1895. Polar Geography, 37(2), 157-176. The errors do not affect the conclusions of the paper, which suggest that further quantitative research is needed into the Sami geography of hydro energy development in Jokkmokk (and elsewhere). Such research would need to consult original Census records and be guided by people with local cultural knowledge. We apologise for any inconvenience caused to readers, and particularly apologise to any offence that may have been felt by Sami people.