OPP report they were called to the single vehicle collision on an Ontario Federation of Snowmobile Clubs trail in Carling Township.
The 31-year-old woman was driving the snowmobile. She was taken to hospital, where she died of injuries.
The trail, which was closed for investigation, has since been reopened.
The cause of the crash has not yet been released.
Deaths down, crashes up
OPP in northeastern Ontario said that, so far this year, the number of snowmobile fatalities is down compared to last year.
Last winter, there were five snowmobile deaths by this time in the season. This year, OPP report there have been three, including the death on Tuesday in Carling Township.
However, police said despite the lower number of fatalities, officers have responded to more collisions: 20 so far this year compared to 15 last year.
Speed and alcohol remain contributing factors in the majority of collisions, OPP said.