Next to the museum, in the rooms of the Museum of Local History in Sonntag is an archive in which certificates, files and writings are kept. Researchers from outside of the valley find sources on the history of the Grosses Walsertal in national, state, town and community archives. Archive materials are also in the possession of private individuals, associations and businesses.

In order to make it easier to research the history of the Grosses Walsertal, the Grosses Walsertal Homeland Association is working on building up a “research database” which will contain sources concerning the Grosses Walsertal or the population of the valley.