Today #Borders studies the lines traced between Norway and Finland during the 19th century.
The Finland/Norway border was defined, as we have seen, during the 1751 Strömstad treaty between the Kingdom of Sweden, which was ruling Finland at the time, and the Crown of Denmark, ruling Norway. After Finland became the Grand Duchy of Finland, in 1809 (a Grand Duchy of the Russian Empire), and the independent Kingdom of Norway was evoked (in personal union with Sweden) in 1814, a new border treaty was negotiated in 1816, defining the exact border zone and confirming the right for the Sami people to cross the border freely, including their reindeers, as they always had done. In 1852, the border of Norway–Finland/Russia was closed, causing trouble for the Sami, who needed the Finnish forests for reindeer winter grazing; and between 1920 and 1944, the Petsamo area was ceded by Russia to Finland, and then re-occupied in 1944.
Today, the Finland–Norway border is 736km long; but as both countries are part of the Schengen area, it is an open border, punctuated by 57 original cairns, man-made stack of stones, across the route, with a letter and a number. Kansallisarkisto holds the Carte Topographiques de la ligne de demarcation Entre le Grand-Duche de Finlande et le Royaume de Norvega between 1827 and 1897.
Check out the documents here:
http://www.archivesportaleurope.net/ead-display/-/ead/pl/aicode/FI-1/type/fa/id/VAKKA-276588.KA/unitid/FI_SLASH_FI-HeNAF_SLASH_Rk+RkN+1_SLASH_-+-/search/3/FI_SLASH_FI-HeNAF_SLASH_Rk