DULUTH, MN (KDAL) - The John Beargrease Sled Dog Marathon got underway in Duluth Sunday afternoon.  Ten mushers and their teams of dogs are on the trail in the marathon and 30 remain in the mid distance race.  As of Monday morning, Jenny Greger from Bozeman, Montana has the lead in the mid distance race, followed by Erin Altemus from Glenwood City, Wisconsin and Martha Schouweller from Irma, Wisconsin.  The marathon is led by Andrew Letzring of Herbster, Wisconsin, in second place is Keith Alli from Ray, Minnesota and Nathan Schroeder from Chisholm is in third.  The mid distance race finishes in Tofte with the first mushers due in sometime today.