They appear to have had two long-lasting communities in Greenland, and a site has been found at L'Anse aux Meadows in Newfoundland.
But is there any solid evidence that the Vikings had a more extensive presence in pre-Columbian North America?
If there was an extensive Viking presence in North America, it has not been documented. And the doings of the "western" (Norwegian) Vikings are fairly well documented. What would be accurate illustrations of vikings and viking culture?
One of the issues is that the Vikings didn't "know" that they had "discovered" (or were close to discovering), a new continent. To them, Newfoundland (an island) was just another Greenland or Iceland, somewhere in the Atlantic Ocean, with no particular relevance to anything else.
There is some various "evidence", but all of it is of such low quality or shaky provenence that they are generally considered fakes. For example, we have the Heavener Runestone, in Oklahoma. The writing scheme employed, Elder Futhark runes, were used far before the other Viking excursions into North America, and two of the runes are incorrect. There are a few other proported Viking artifacts in Oklahoma, but all are generally accounted as either similar low-quality modern fakes, or more likely Native American in origin.
There is also the Kensington Runestone, from Minnesota. It also seems to be a forgery, although a slightly better done one.
Then there are the Beardmore Relics. These appear to be genuine iron Viking-age artifacts, supposedly found in Ontario. Their authenticity is not in a lot of doubt, but most scholars believe they were probably planted in Ontario. The son of the "finder" signed a sworn affadavit that they were in fact planted there by his father.
So there are hints of Viking activity around Oklahoma and the western Great Lakes area, but most likely that has more to do with modern scandanavians settling in those areas than any actual Viking activity there. There's no real accepted evidence of a Viking presence in North America outside of Greenland and Newfoundland.