Yes, there's actually a language called Elfdalian

Just a quick FYI for those interested in Scandinavian languages - there's a language located near central Sweden called Elfdalian, spoken by about 3000 and thus extremely endangered. It's also quite conservative, retaining many features seen in Old Norse that have since been lost in other Scandinavian languages. An article here in Swedish can be read about Elfdalian being a language and not a Swedish dialect, and another one here is of the opinion that Swedish is a threat to Elfdalian. Just about any language would be, when you're dealing with a language with such a small population.

Quick note: beware when using Google Translate to read articles on languages, as it always gets names of languages confused and more often than not will call them all English. I see it also calls Elfdalian "river's wife" in the second article.

Just how unknown is Elfdalian? Google News turns up exactly 0 articles on the language. YouTube, however, has a bit of content. Here's a song in Elfdalian.