By January of 1833, Lönnrot had moved to Kajaani. He was to settle in Kainuu for two decades, which afforded him a base for all the poetry-collecting journeys he would make. Lönnrot's fourth field trip was the most important for the creation of the Kalevala, because it was then that he came upon the idea of compiling an epic from the folk poetry he had collected. His route through Kainuu on the field trip is well recorded: it was his work again that forced him to travel, but he decided to include a ten-day visit to Viena to collect poetry.

In November of the same year, Lönnrot sent an account of his trip to J.L. Runeberg, who published it the following year in Helsingfors Morgenblad, a paper of which he was the editor.

After his successful poetry-collecting trip to the village of Vuokkiniemi, Lönnrot went on via Akonlahti to Kuhmo, where he finished his account of the trip at the Juortana house.

Lönnrot's fourth field trip yielded 49 poems, comprising 2.900 lines.