Eagle Cap is located in Wallowa County, in the Northeastern corner of Oregon, and was thought to be the highest mountain in eastern Oregon, hence the name. For many years there was no exact measurement of its altitude. Some later observations by the United States Surveyor General put the height at about 9,595 feet. Apparently there are other peaks in the Wallowa Mountains that are higher.

Wallowa is a Nez Perce Indian word to describe a network of sticks used for catching fish. These traps were put in Wallowa River below the outlet of Wallowa Lake.