Martin Poulin and Francine Dumas, both 57, left Quebec for a wedding in Hampton Beach on July 28, but never arrived.
Family members filed a missing persons report with Quebec provincial police on Saturday. Investigators found neither the cellphones nor the credit cards of the couple had been used.
Loved ones scoured the route the couple were expected to travel, and located their Nissan Altima on Route 201 in Somerset County, Maine, about 380 kilometres short of their destination.
The search party flagged down a police officer, and collision investigators were dispatched to the scene.
The Somerset County Sheriff's office said the car left the road and struck a tree in a heavily wooded area.
The tree then fell onto the vehicle, hiding it from view from the road.
The crash is still under investigation.