Afternoon storm risk is the line that matters. Everything else is comfort. In summer, plan to be off the ridge before the build-up starts, not as it starts. Forecast for the summit point, adjusted for its elevation · data from Open-Meteo.
Standard route · Northeast Ridge
Overview
Mount Eolus is the most demanding of the Chicago Basin 14ers. From a camp in the basin it is about 6 miles round trip with 3,100 feet of gain. Most people take 6 to 9 hours from camp. The climb goes up to Twin Lakes, across a rocky basin, up a ledge ramp, over a narrow ridge called the Catwalk, and then up the steep east face on narrow ledges.
The route is Class 3 with high exposure and real route-finding. The Catwalk is mostly easy, but the drops on both sides are big. The last 250 feet to the summit are the crux: there is no trail, and you have to find a line of ledges up the face. A fall from the upper face or the Catwalk could be fatal.
Eolus suits climbers who are already comfortable on Class 3 rock and exposure. It is remote. You are a train ride and a 6-mile hike from the nearest road, so help is many hours away. Climb it with a partner, start early, and turn back if the rock is wet or icy.
Plan of the day
Start by
By 4:30 to 5 a.m. from camp. Storms in the San Juans often build by late morning, and you want to be off the Catwalk and upper face before then.
Turnaround
If you are not at the notch on the Eolus-North Eolus ridge (about 13,850 feet) by 10 a.m., turn around. Do not start up the final face if clouds are building; the ledges are hard to down-climb in rain.
Crux
The final 250 feet up the east face. You traverse left below rock walls, then climb back and forth on steep, narrow ledges to the summit ridge. The Catwalk before it is exposed but easier.
Route-finding
The trail to Twin Lakes is clear. Above the lakes, cairns mark the way, but the ramp entrance, the green chute to the ridge, and the ledges on the final face all take careful route-finding. The upper face is where most people get off route.
Water
Needle Creek near camp, the streams below Twin Lakes, and Twin Lakes itself. There is no water above the lakes. Filter everything. Fill up at Twin Lakes on the way up.
No cars. You must take the Durango & Silverton Narrow Gauge Railroad deep into the wilderness and get dropped off at a riverside stop called Needleton.
Terrain
A remote, multi-day backpacking expedition. You hike 6 miles from the train into a high alpine basin, set up a basecamp, and climb from there.
This is a full wilderness adventure. After backpacking into the stunning Chicago Basin (filled with mountain goats), you launch your summit bids from your tent. Windom is a fun scramble up solid granite blocks. Eolus involves a breathtaking, exposed traverse across a narrow rock sidewalk called the "Catwalk." Sunlight is the hardest—requiring a terrifying move to stand on a tiny, exposed summit block with nothing but air below you. It is the ultimate remote 14er experience.
The trip starts at the Durango and Silverton Narrow Gauge Railroad station in Durango; signs in town point the way. Reserve a seat ahead of time on a train that stops at Needleton. The ride is about 2.5 hours. At Needleton, cross the bridge over the Animas River and hike up the Needle Creek trail about 6 miles and 2,800 feet to Chicago Basin. Plan the return train carefully; missing it can mean another night out.
Camp in the basin, where dispersed sites are found between about 10,800 and 11,100 feet. This is Weminuche Wilderness, so follow wilderness rules. Mountain goats in the basin are bold and seek out salt; hang or guard your gear and urinate on rock away from camp. The mileage below starts from a camp near 11,100 feet.
Needleton / Chicago Basin (Train Access). Road conditions near the trailhead change after storms. Check your clearance and have a backup plan for a lower lot.
Trail in the treesScramblingTundraTalus and screeRidgeExposed to lightning
The line is elevation, the band underneath is the ground, and the numbered dots match the steps below. Mileage and elevations are approximate.
1
Chicago Basin camp 11,100' · 0 mi
From camp, follow the main trail northeast toward the head of the basin. It is wide and easy here.
Chicago Basin from below Jupiter Mountain · Photo: SFC H
2
Twin Lakes junction 11,200' · 0.3 mi
Near 11,200 feet, turn left at a signed junction toward Twin Lakes. This trail serves Eolus, Sunlight, and Windom.
Watch for: Do not continue straight up the basin toward Columbine Pass.
3
Slabs in the trees 11,350' · 0.5 mi
The trail climbs through the last of the forest. It gets harder to follow as it crosses rocky slabs. Look for the worn path across the rock.
4
Out of the trees 11,400' · 0.6 mi
Leave the trees near 11,400 feet. Two streams run down the slope below Twin Lakes. You can see the headwall you will climb.
5
First stream crossing 11,700' · 0.8 mi
At about 11,700 feet, cross the first stream. Go right and follow switchbacks up the steeper slope.
Watch for: Wet rock at stream crossings can be slick, and may be icy early in the morning.
6
Second stream crossing 12,300' · 1.3 mi
Cross the second stream near 12,300 feet. Keep climbing on the trail up the last of the headwall.
7
Twin Lakes 12,500' · 1.5 mi
Reach Twin Lakes at about 12,500 feet. This is a good place to fill water. Near the first lake, find the Eolus trail branching off to the left.
Watch for: Last water on the route.
8
Lake outlet crossing 12,500' · 1.6 mi
Follow the Eolus trail down to the stream at the end of the lake. Cross it, walk past some rock slabs, and head west.
9
Traverse below cliffs 12,900' · 1.9 mi
The trail traverses around cliffs on your right. Soon the east face of Eolus comes into view ahead. It looks steep; the route goes up it on ledges.
10
Boulder field 13,300' · 2.2 mi
Near 13,300 feet the trail curves left into a boulder field. Follow the rocky path with built-up steps through the boulders. It exits near 13,400 feet.
11
Ledge ramp 13,450' · 2.35 mi
Climb a little higher to the base of a ledge or ramp that leads up and out of the basin. Look for a cairn at its start. Turn right and climb northeast up the ramp. It stays Class 2, but a couple of spots cross tilted slabs.
Watch for: Slabs are slick when wet or icy. Move carefully.
12
Flat area below the ridge 13,650' · 2.5 mi
At the top of the ramp, go north on easier ground to a flat area east of the ridge between Eolus and North Eolus. Look west at the ridge for a notch just above a short, steep, green-tinged chute.
13
Notch on the ridge 13,850' · 2.65 mi
Climb to the notch. The direct way is up the green chute with a short bit of Class 3. An easier option goes a little right and zigzags up tilted slabs. At the notch, turn left (south) toward Eolus.
Watch for: North Eolus is to the right. Eolus is to the left.
The ridge between North Eolus and Eolus · Photo: Robert Tadlock
14
The Catwalk 13,850' · 2.75 mi
Climb over a small bump on the ridge, then drop a little to the Catwalk, a narrow section of ridge. Most of it is Class 2, with a few easy Class 3 moves. The drops on both sides are large. Take your time.
Watch for: High exposure on both sides. Do not cross in high wind or lightning.
15
Base of the east face 13,850' · 2.85 mi
At the end of the Catwalk, easier ground leads to the base of the final summit climb. The northeast ridge rises straight above you, but the easier way is on the east face, to the left. Traverse left below rock walls to about the middle of the face.
Watch for: The ridge straight up is harder than the face. Stay left.
16
Summit 14,087' · 3 mi
Turn up and zigzag on ledges. It gets steeper as you go and the ledges get narrower. Reach the summit ridge and scramble a short way to the top. You can see Sunlight, Windom, and the Needle Mountains all around.
Watch for: Narrow, exposed ledges. Test holds. Do not climb here if the rock is wet or icy.
The top of Mount Eolus · Photo: Jeremiah LaRocco
Along the route
Chicago Basin · Photo: Dusty JMorning light on the ridge near Eolus · Photo: kalestews
Here Needle Creek Trail (504) goes off straight ahead. Keep left to follow Chicago Basin Trail.
Coming down: Keep going straight on Needle/Johnson Creek Trail. Don’t take Needle Creek Trail (504).
2Mile 2.8 · 13,850'
Turn left onto The Catwalk
Here an unmarked path goes off straight ahead. Turn left to follow The Catwalk.
Coming down: Turn right to stay on the trail you came up. Don’t take the unmarked path.
Landmarks to know
The signed Twin Lakes junction near 11,200 feet.
Two streams on the slope below Twin Lakes.
Twin Lakes at 12,500 feet, with the Eolus trail going left.
The boulder field with built-up rock steps near 13,300 feet.
A cairn at the base of the ledge ramp leading northeast.
The green chute below a notch on the Eolus-North Eolus ridge.
The narrow Catwalk ridge heading south to Eolus.
The steep east face, climbed on ledges left of the northeast ridge.
Getting down
Down-climb the east face the same way. Facing in on the steep ledges is often safer. It is easy to lose your line coming down; look for the ledges you came up and traverse back right (north) toward the end of the Catwalk. Do not try to go straight down the face or the northeast ridge.
Recross the Catwalk, go over the small bump, and drop off the ridge at the notch. Use the green chute or the slabs to reach the flat area. Then find the top of the ramp. It is easy to miss; take a look at it on the way up. Follow the ramp down, go through the boulder field, and take the trail back to Twin Lakes and camp.
If things go wrong
The route has only one safe way down, the way you came. The notch on the ridge and the flat area below it are the key points; below the ramp you are back on easier ground. If storms build, get off the Catwalk and the ridge first. Then descend the ramp to the basin. Do not try to shortcut down other gullies from the ridge; they are loose and cliffed. If someone is hurt, keep them warm, stable, and out of the rockfall line. Call 911 if you have a signal, but coverage is poor and rescue from Chicago Basin takes many hours. Carry a satellite messenger if you have one, and know that other climbers at Twin Lakes may be able to help.
3D flyover
Press play to fly the Northeast Ridge. The graph shows elevation along the way and how much you gain each mile. Open full screen.
For planning only. The line is traced from open map data, not walked in the field, and off-trail parts are drawn straight. Load it in your GPS app to see the route, but navigate with your eyes, a map and the route description.
See the trail on video
A climb of this route filmed by The Virtual sherpa. The video belongs to them and only plays when you press play. This video covers North Eolus and Eolus together.
Jump to
Other routes
All 1 route up Mount Eolus, with the class and round-trip distance for each.
TypeRouteClassTrailheadRound trip
Standard
Northeast Ridge
Class 3
Needleton (Durango & Silverton train)6 mi · 3,100'Full route →
The ultimate single-day wilderness push matching four separate high points. You launch from a remote camp, scrambling across the high-exposure Catwalk on Eolus, dropping down into the basin floor, ascending the giant blocky granite boulder fields of Windom, and finishing with the technical, exposed chimney cracks of Sunlight Peak's Red Chute.
Link-upChicago Basin QuadClass 4
Mount Eolus → North Eolus → Sunlight Peak → Windom Peak
The ultimate single-day wilderness push matching four separate high points. You launch from a remote camp, scrambling across the high-exposure Catwalk on Eolus, dropping down into the basin floor, ascending the giant blocky granite boulder fields of Windom, and finishing with the technical, exposed chimney cracks of Sunlight Peak's Red Chute.
From the trail
Our photos from Mount Eolus
This is a climb, not a hike
Class 3 means sustained scrambling with your hands, on terrain where a fall has real consequence. Build up on easier scrambles first, wear a helmet, go with someone who has led this kind of ground, and remember that downclimbing is harder than going up.
