According to the National Park Service, nearly 78,000 people visited the caves along Lake Superior from Jan. 15 through the end of February.
The last time the ice was thick enough for people to walk on to see the caves was in 2009, but only about 8,400 visited in January and February.
Julie Van Stappen, with the Apostle Islands National Lakeshore, has said social media is playing a bigger role this year in getting the word out.
It's unclear how long the lake ice will be sturdy enough to handle visitors. Park officials say one of the longest seasons was probably in 2009, when the caves were accessible for February and March.