Atlantic Peak, once listed as UN 13,841, sits just south of Pacific Peak on the Tenmile crest southwest of Breckenridge. It is a quieter neighbor to Quandary Peak, and with Pacific and Crystal Peak nearby it is often the first stop on a three-Centennial circuit.
From the east, the Northeast Slope starts in McCullough Gulch, where summer parking is managed with permits and a shuttle. A maintained trail with log bridges climbs past waterfalls (route-finding gets confusing near 11,800 feet) and fades above 12,400 feet. Then comes about half a mile of rough talus to a loose headwall, the crux, which tops out just below the Atlantic and Pacific saddle before a final ridge walk. Plan on about 7 miles and 2,900 feet of gain at difficult Class 2. From the west, the West Ridge leaves the Mayflower Gulch trailhead, follows Pacific Creek and climbs mostly stable talus, staying left of the crest through a steeper section near 13,300 feet. It is the shortest line at about 4 miles and 2,450 feet.
The summit sits close to the northwest of Quandary's top and looks straight across to Pacific and down into lake-filled basins that fill with wildflowers in midsummer. The ridges are exposed to afternoon lightning, so start early and turn around when clouds build. Snow lingers on the headwall, and an axe and crampons are the right call when it does.
