He also documented many of the stories elderly people in the villages told him and was very active in the Swedish local heritage movement that started in the 1920s.

He describes weddings, people, interiors, transhumance, and village streets with a great sense of feeling for composition and quality.

The documentary work procedure of Lärka is also shown in his recording of older people's stories, a method he combined with his photography.

Later he changed for a larger-format American camera acquired from a retailer who had bought it for photographing thieves in his shop at Sollerön.

When the first sheet film arrived, his work was made easier and there was no longer any risk that the light would disappear while reloading, which sometimes had happened before.

When he was thirteen he was taught by Uno Stadius, who had a folk high school at Sollerön and told Lärka the importance of documenting everything he observed regarding culture and history.

There he got to know the district court judge Lars Trotzig, who understood Lärka's talent and tried to help him get a scholarship for an education in civil engineering at the Royal Institute of Technology in Stockholm.

[12] Thanks to his contacts with Trotzig and later on Anders Zorn, Lärka got the opportunity to work with some building restoration projects.

Instead, he took winter courses at the folk high school of Brunnsvik in 1915–1917 and became good friends with his classmate Dan Andersson.

It is known that he was not that interested in the categorizing of the people of Dalarna in different groups according to their skulls, and preferred to listen to the stories of the old men.

[14] Lärka tried to get the Nordic Museum interested in making an inventory of the parish of Sollerön and tried to get funds to gather his notes and photos.

Lärka lectured during 1920 all over Sweden, often dressed in Sollerö costume and sometimes together with the folk musician Axel Myrman.

[20] As the great burial ground from the Viking Age was discovered at Sollerön in 1928, Karl Lärka became very engaged in investigating and preserving it for future generations.

Lärka spent a lot of time trying to preserve the burial ground from the destruction due to farming and stone-clearing operations.

[22] The work at their farm, his engagement for the burial ground, and the couple's poor incomes meant there was neither money nor time for Karl Lärka to go on photographing.