Grandma's Marathon began in 1977 when a group of local runners planned a scenic road race from Two Harbors to Duluth, Minnesota. There were just 150 participants that year, but organizers knew they had discovered something special.

The marathon received its name from the Duluth-based group of famous Grandma's restaurants, its first major sponsor. The level of sponsorship with the restaurants has changed, but the race has retained its name. Grandma's Marathon is now a self-governed nonprofit organization with a 17-member board of directors. Grandma's Marathon weekend draws more than 17,000 participants for its three-race event each June.