Troms og Finnmark was a county in northern Norway that existed from 2020 to 2023. The county was established on 1 January 2020 as the result of a regional reform. It was the largest county by area in Norway, encompassing about 75,000 square kilometres, and was formed by the merger of the former Finnmark and Troms counties in addition to Tjelā¦Troms og Finnmark was a county in northern Norway that existed from 2020 to 2023. The county was established on 1 January 2020 as the result of a regional reform. It was the largest county by area in Norway, encompassing about 75,000 square kilometres, and was formed by the merger of the former Finnmark and Troms counties in addition to Tjeldsund Municipality from Nordland county.