According to Official Guinness Records,
The greatest distance in 24 hours on a snowmobile was 3,069.12 km (1,907.06 mi) achieved by Nicholas Musters (Canada) in Lake of Bays, Ontario, Canada on 8-9 March 2011. He completed 303 laps on a 10.129 km course.
He began the event on a 2011 MXZ TNT 800 E-TEC and ultimately completed it on a 2010 MXZX 800 E-TEC after his first vehicle malfunctioned.
For a complete list of 2011 records, please visit 2011 Guinness Records in Canada.