According to Official Guinness Records,
The greatest distance walked using snowshoes in 24 hours is 94.41 km (58.66 miles) and was achieved by Thomas Müller and Heiko Becher (both Germany) between Gräfenwarth and Saalburg, Germany, on 28 December 2010. The route between the two towns was repeatedly covered to achieve the record distance. During the attempt, they also covered a total of 2,022 vertical metres.
For a complete list of 2010 records, please visit 2010 Guinness Records in Germany.