Two great mountain ranges intersect in Lake Clark National Park and Preserve. The Neacola Mountains in the north central part of the park belong to the Alaska Range, the spectacular array of peaks that includes Mt. McKinley, the tallest mountain in North America. The Chigmit Mountains in the south and west part of the park are part of the Aleutian Range, which contains dozens of volcanoes.

The pass between the Neacola and Chigmit ranges is Lake Clark Pass. The pass is at an elevation of 1,050 feet above sea level, and is more than 9,000 feet below the peak of Mt. Redoubt, which towers over the pass to the south.

The tallest mountains in the park are both active volcanoes: Mount Redoubt, at 10,197 feet, and Mount Iliamna, at 10,016 feet. Telaquana Mountain peaks at 8,050 feet tall.