Mount O'Neel is located in the Chugach Mountains, 34 miles (55 km) east-northeast of Cordova and 2.5 mi (4 km) southeast of Mount Williams, on land managed by Chugach National Forest.

Although modest in elevation, topographic relief is significant since the south face of the mountain rises up over 5,400 feet (1,646 m) in less than one mile from the immense Childs Glacier.

The peak was named about 1910 by Lawrence Martin, for A. C. O'Neel, Chief Bridge Engineer for Copper River and Northwestern Railway, who built a $1,500,000 steel bridge across the Copper River near the southeast base of this mountain in 1909–1910.

[4] Weather systems coming off the Gulf of Alaska are forced upwards by the Chugach Mountains (orographic lift), causing heavy rainfall.

The months May through June offer the most favorable weather for viewing and climbing.