Atlantic Peak Route Guide | A Great Ten-Mile 13er

The Mosquito and Ten Mile Ranges are home to a number of enjoyable peaks, including this Atlantic Peak Route Guide. Located just north of Quandary Peak, a popular fourteener, this centennial 13er is one of the highest peaks in the state. Compared to 14er routes, you’ll find plenty of solitude on this route, especially once you pass the alpine lakes along the way. If you plan to do this climb in the spring or early summer, bring crampons and an ice axe for the headwall crux of the route. Plan your visit with my Atlantic Peak Route Guide below.

New to 13ers? Check Out my Beginners Guide Here to Get Started!

Atlantic Peak Route Guide Fast Facts

Atlantic Peak Route Guide - Northeast Slope

Park at the gate and start hiking along the road up McCullough Gulch. Parking here along the road fills quickly, so it’s a good idea to arrive early to ensure you find a spot. After around half a mile, take a trail to the left of the road and head into the forest. 

Near 11,600 there are several waterfalls. You can take a social trail to view the falls, or stick to the main path on the right to climb over this moraine. You’ll come to a beautiful alpine lake, with many dispersed camping sites around it.

Head along the north side of the lake along the trail, and look for a ramp along the stone moraine ahead of you. Follow cairns and trail segments that take you up into the upper Basin. 

The trail here will begin to fade as you near another lake around 12,500 feet. Angle northwest and climb a rib that separates you from a the northern half of the basin.

From here, you have a half-mile talus hop to reach the bottom of the headwall. You’ll climb this to reach the saddle that lies between Atlantic and Pacific Peak. The headwall holds snow late into the year. It’s a good idea to bring an ice axe and crampons in case you come across snow. Take your time climbing this headwall, sticking to the center for the least steep climb.

From the top of the headwall you have two options. You can immediately veer left to ascend the northeast slope, or continue to the north ridge to ascend it to the summit. From here you can easily add on a summit of Pacific Peak to the north, a ridge traverse away.

At the summit, enjoy your achievement! Make sure you descend with plenty of time to reach the trailhead before afternoon thunderstorms become a problem. I hope you enjoyed my Atlantic Peak Route Guide.

Atlantic Peak Route Guide

Hiking & climbing 13ers or 14ers is an inherently high-risk activity – do so at your own risk, and use the following best practices to help keep yourself safe.

  1. Research your route and bring a compass & topographic map.
  2. Check the weather forecast and stay home during inclement weather.
  3. Bring the Ten Essentials and the knowledge/skill to use them.
  4. Leave your plans with someone back home along with a detailed itinerary.
  5. Start early, and end early: Be back at tree line by noon to avoid lightning.
  6. Bring a buddy on your first ascent, preferably someone experienced.


Hiking, scrambling and climbing up Colorado’s high peaks are inherently high-risk, dangerous activities. There is a significant risk of injury or death, even with proper planning and experience. Those using my Atlantic Peak route guide accept all risks associated with climbing 14ers and 13ers do not hold this website or any information they obtain from it liable for any accidents or injuries that occur while engaging in these activities on Colorado’s high peaks. It is each hiker or climber’s responsibility to research their route carefully, bring the ten essentials, and practice other safe practices, though even these precautions do not eliminate risk and danger. Visit these summits at your own risk.


About the Author: Alex Derr

Alex Derr is a mountaineer and blogger based in Denver Colorado. He is working to climb Colorado’s highest 100 peaks, and the 20 tallest peaks in California. He created The Next Summit to share advice, stories, history & reflections from the Colorado Rockies & Sierra Nevada. When not climbing, he is managing the Communications strategy at Visible Network Labs.