Nearly everything about Lake McConaughy is big. At full storage of 1,948,000 acre-feet, Big Mac is 22 miles long, 4 miles wide for quite some distance from the dam, and 142 feet deep near the dam. When full, Nebraska's largest reservoir is 35,700 acres and has 105 miles of shore line with many sand beaches. Its dam is among the largest of its type in the world, and its fish grow to trophy proportions, accounting for several state records. Even its nickname, "Big Mac". reflects the lake's giant stature.