The Cessna 182 left Anchorage on Monday morning for Takotna, a village of 53 on the route of the Iditarod.
The plane was due into the village at noon and was reported overdue at 4 p.m.
Guard spokeswoman Kalei Rupp said aerial searchers spotted wreckage at 10:22 a.m. Tuesday near the 4,000 foot level of Rainy Pass. They landed and found the bodies.
The names of the people killed have not been released.
The airplane was not part of the Iditarod Air Force that carries volunteers and supplies, and delivers race dogs between communities.