title: Hells Canyon
context: Hells Canyon is  a 10-mile-wide (16km) canyon located along the border of eastern Oregon, eastern Washington and western Idaho in the United States.  It is part of the Hells Canyon National Recreation Area and is North America's deepest river gorge[2] at 7,993 feet (2,436m).[3]
question: Where is the deepest canyon in the United States?
answers: Hells Canyon