The Finnish Bryophyte Expert Group went to its annual excursion to the Tiilikkajärvi National Park in Rautavaara and Sotkamo communes on the border between Karelia borealis and Ostrobothnia kajanensis biogeographical provinces in August 2025. Tiilikkajärvi National Park is characterized by vast aapa mires and boreal forests in addition to lake, river and esker ecosystems. We visited field sites with old-growth forests, cliffs, springs, river shores, mires and nutrient-rich fens. Altogether 205 bryophyte species were detected. These included 139 species of mosses and 66 species of liverworts. Four species new to Karelia borealis biogeographical province were recorded. The most noteworthy record was Nardia compressa, which was found in river Tiilikkajoki near Sammakkotammi. The species is classified as Vulnerable in Finland and has only four occurrences in the country so far, the closest one being about 200 km away from Tiilikkajärvi. Also, the new findings of Fontinalis dichelymoides and Imbribryum subapiculatum expand the range of both the species remarkably. We present a complete list of the observed species together with information on their localities.