Mt. Conness at 12,590 ft. is the highest peak on the northeast border of Yosemite National Park. The snow fields on the upper flank of the mountain are the last remnents of Conness Glacier. Although it has lost half its surface area in the last two decades, Conness Glacier is still the largest glacier in Sierra north of Tioga Pass. The Conness Lakes are glacial tarns -- pools in depressions carved out by the glacier. Hoover Wilderness Area. Inyo National Forest. Mono Co., Calif.