Chopaka Mountain, Mountain summit in Okanogan County, Washington, United States

Chopaka Mountain, also called Mount Chopaka, is a summit on the leeward flank of the North Cascades in Okanogan County, Washington. Its summit area is a 2,764-acre Natural Area Preserve. The mountain rises to 2,403.99 metres above sea level and supports a mountain goat population and rare plants.

The mountain was home to Washington's last wild bighorn sheep population until the 1920s, when hunting eliminated them entirely. This extinction marked the end of a native animal population that had inhabited the region for generations.

The name Chopaka, per the British Columbia Geographical Names Information System, may refer to an Okanagan hunter turned to stone by Coyote, or to a maiden transformed into stone. Climbing guide author Fred Beckey instead gives it as an Indian word meaning "high mountain".

Chopaka Mountain's 2,764-acre summit area is a Natural Area Preserve, so access is managed rather than open recreation. A Washington State Discover Pass is required for parking, and visitors planning research or group activities should contact the regional managers beforehand. Developed facilities are minimal, so plan for self-sufficiency.

The protected area harbors eleven rare plant species found on the state listing, including special gentians, cinquefoils, and moonworts that grow nowhere else nearby. This botanical diversity makes the preserve particularly important for conservation of these delicate species.