Mt. Eolus

Route: Northeast Ridge
Posted On: 7/6/2026, By: 5ClimbingCooneys
Info: This is a horrible peak, but it's dry and clear of any snow that would affect the standard climb. It's a long rocky slog followed by a convoluted mess of wrong way spurs weaving across exposed, sandy ledges. There are false paths and cairns everywhere. Climbed it 20 years ago before it had to deteriorated to this level and it's sad to see how bad it's gotten. The catwalk is the only enjoyable portion of this route. If you have a fear of heights, stay away from this peak. Also, highly recommend climbing with the smallest pack possible. Do not even for a moment consider leaving or stashing your gear anywhere on this peak as the marmot army has overrun the peak and claimed it as their HQ in the region. 

Route: Chicago Basin Approach
Posted On: 6/25/2026, By: wmagnuson7
Info: Almost entirely summer conditions, but the area below the notch leading up to Eolus and North Eolus still holding a significant amount of snow, so microspikes or poles may be helpful. Otherwise, a gorgeous weekend in Chicago Basin! 

Route: Chicago Basin Approach
Posted On: 6/13/2026, By: Craig Barlow
Info: Started from Chicago Basin at 4:30am. Crossed 2 snowfields on the way to the Eolus / North Eolus saddle. Snow was still firm as it was 6am, but managed both very easily with trail runners and poles by utilizing previous bootprints. North Eolus summit at 6:35am, Eolus summit at 7:15am. One small snow patch ro cross at base of Eolus with very nice footprints through other. Snow softening on the way down by 8am was great for bootsking and no postholing.

Back to Twin Lakes at 8:35am, then started up Sunlight. Some low angle (almost flat) snowfields with postholing near the edges, still solid in the middles. One very minor snowfield to cross about 100' below the summit which has great footprints through it and this can also be avoided. Sunlight summit at 9:55am.

Large snowfield to cross in the bowl between Sunlight and Windom. Following previous footprints worked OK, but bad postholing otherwise now around 10:45am. A couple tiny snowfields just below Windom summit at 11:45am with good footprints through them.

In summary, you don't really need any traction if you are experienced, imo.

Continued to Jupiter after Windom. The snow up the north face was horrific and I was swimming up to my waist in soft snow. Finally got to a rock rib which saved me and was Class 2. A couple final short steep snowfields before getting to the summit ridge were actually pretty firm and I used the pick of my axe (didn't have crampons) but my trail runners were able to just get enough purchase. No snow on summit ridge or on descent towards Columbine Pass trail. 

Route: Chicago Basin Approach
Posted On: 6/8/2026, By: owen_farkas
Info: This is for the whole Eolus group, just didnt want to post seperately.
Approach: I hiked in from Purgatory. There are a substantial amount of downed trees and muddy areas on the trail leading to Chi Basin. No snow on approach. Twin Lakes is frozen and there is substantial snow from then on.
Windom: This peak is currently a (easy) snow climb to the ridge. The ridge on is mostly dry but there are a few portions where snow blocks the main route.
Sunlight: The least snow of the 4. Some snow travel is required to access the South face but past then you can avoid snow to the ridge. The class 4 move (not summit) has snow on it making it awkward. Summit area is totally dry.
Eolus: Trail is snow covered beginning at around 13000'. From here, up the ramp, and to the bottom of the notch is an easy/moderate snow climb. Fun glissading down in the afternoon, though. Catwalk and ledges are dry, but there is 1 unavoidable snow drift between these 2 sections. No traction needed, but it will make your shoes wet. N Eolus ridge is dry
I summitted all 4 with microspikes & ice axe. I would recommend crampons for Eolus.
One of my (blue) hiking poles got stolen by marmots at twin lakes. I could't find it up there. Sorry that I left a trace! :( 

Route: Chicago Basin Approach
Posted On: 5/26/2026, By: slawrence2011
Info: See my sunlight post for overall context of the trip. Basin below is melted trail until about 1K below couloir. Couloir unfortunately has taken a beating from the sun, especially near the bottom. Very sloppy down there with rocks getting exposed. Unfortunately, I wouldn't rely on this remaining skiable for long. In it's current state though, managed to ski all of it except the top choke, which stayed shady and wind slabby, and I side stepped. Also, had to do a couple side steps near the bottom due to runnels forming. Note that you can't really see this until you start climbing one of the other peaks, it looks horribly out from lower twin lakes. Summit scramble is dry. 

Route: Chicago Basin Approach
Posted On: 5/14/2026, By: ericahlstedt
Info: The trail to to chicago basin and up to twin lakes is pretty much dry and snow free. There is continuous snow at and after twin lakes.

We hiked up the standard trail just a short way before skinning to the base of the NE couloir. At the top of the couloir its a 3rd class scramble to the summit along the South ridge. 

Route: Chicago Basin Approach
Posted On: 10/3/2025, By: aprb
Info: The South Ridge on N. Eolus was dry. Some snow on the catwalk, but easily avoidable. After the catwalk, muddy on the Eolus ledges. The weekend before, it snowed 2" according to the NOAA forecast; This condition update was 2 bluebird days after the first snow. Sunlight looked dry. Windom looked like it held some snow. 

Route: Chicago Basin Approach
Posted On: 7/24/2025, By: usfgal
Info: No snow on this route or N. Eolus, but the trail and rock were both wet from all the recent rain. It was okay, but be careful past the catwalk on Eolus- the rock seemed slick there. 

Route: Chicago Basin Approach
Posted On: 7/15/2025, By: climbingyogi
Info: Very small amount of snow below the green chute leading up to the notch. Pretty easy to get around though.

Definitely try to stay on the 'ledges' as much as possible (and follow the cairns) through the east face leading up to the summit. Found myself making some class 4/5 moves a couple times because I didn't take the time to look for the easiest path. Really enjoyed this one! 

Route: Chicago Basin Approach
Posted On: 7/2/2025, By: kylefwip
Info: Some small snow patches going up near the ramp and the notch, did not need ice axe or microspikes though. Scramble up to peak is clear. Earlier start is good to avoid post holing but not necessary weather dependent. Started around 5 am near Twin lakes trail fork in Chicago basin, did Eolus and N Eolus and was down by 1020, but moved pretty fast. 

Route: Chicago Basin Approach
Posted On: 7/3/2025, By: LSchmidt75
Info: Attempted to summit Mt. Eolus on Day 2 of a Chicago Basin trip after summiting Sunlight and Windom the day before. The approach is relatively clear with some small snow fields that were either navigable or can be circumvented. We carried microspikes and ice axes and didn't need either. The final approach to the saddle between Mt. Eolus and North Eolus was a little tricky taking the snow fields into account. We summitted North Eolus around 8:15 after leaving Chicago Basin at 4:15. The ridgeline on Eolus is clear but felt too spicy and exposed for our tired legs so we said "not today, Satan" - we'll be back another time. We met several groups that summitted Eolus successfully and it is very doable on the right day if you're comfortable with Class III scrambling and exposure, but the route-finding tricky - would leave yourself a good two hours to make it from the saddle to the summit and back. The route up Eolus is easier to see if you summit North Eolus first. 

Route: Chicago Basin Approach
Posted On: 6/24/2025, By: tomboatman11
Info: Trail is great! Mid-May trip report listed 90-something downed trees. Some rockstar trail crews came in and did a ton of axe and saw work to make life easy on us. Enjoy not going over and under spiky downed pines?: Sign in at the trailhead. Steward says the numbers help with funding. And, oh, donate a pen, please. No working pen as of Sunday 6/22.

Snow line is at the Twin Lakes.

Sunlight/ Windom: Plenty of postholing to be had between Twin Lakes and Sunlight (didn’t do Windom, but looks like the same deal).

Eolus: a couple of snowfields to posthole. No snow above the notch.

Snow appears to be melting fast, so expect different conditions if you’re reading this.

Gear: didn’t end up using crampons; snow is too soft. (Again, didn’t do Windom. Crampons might be good for the linkup from Sunlight.) Axe was helpful for controlling and arresting glissades. Helmet per your own risk tolerance. Waterproof, high ankle footwear and gaiters for the snow wallowing.

Look good, have fun, be safe. Use your best judgment. If you don’t know, don’t go. 

Route: Chicago Basin Approach
Posted On: 6/12/2025, By: Jgeeez
Info: Typing this as the train nears Durango. All of the fallen trees are cleared up through Chicago Basin. Still a good amount of snow 12,500’ and up, twin lakes is mostly frozen. The summit ridges of Eolus/N Eolus are clear of snow. All of the Eolus group require snow field climbing right now, and it’s post-holing season! Sunlight had the most snow to climb and it softened real quick in the day. Micro spikes and an ice axe sufficed! 

Route: Chicago Basin Approach
Posted On: 6/2/2025, By: dakotasmama
Info: There are 91 trees across the six miles of trail into Chicago Basin that are large enough you have to climb over, shimmy under, or route find around (at least 91 - every time I wasn’t sure which number I was on, I went with the lower of the two). So keep that in mind when planning how long it will take. I packed in snowshoes for the section above Twin Lakes and they only helped a little - dangerous, deep, soft spring snow conditions all the way up to the notch - I fell and slid backwards approximately 500 feet on the way up, then the snow collapsed under one leg on the way down and it took over 15 minutes to free it. There’s a huge crack about halfway down the couloir and I was terrified it would avalanche the entire time. Once I got to the notch I did Eolus first, lots of mud and running water so I was very careful, especially across the catwalk. After all of that, North Eolus was the quickest, easiest scramble ever. Took nearly 9 hours to go from Chicago Basin to the summits and back. 

Route: Chicago Basin Approach
Posted On: 5/15/2025, By: AlpineSplit
Info: After getting off the train at Needleton, we were able to walk all the way to camp at 11K in runners. There is almost no snow until you get into twin lakes basin at 12K. Once you are on the bench at twin lakes there is plenty of snow and we skinned up to the base of the east couloir and booted up and onto the west side to the summit. West side has continuous snow from the summit, but the summit will only be in for another few days. Good conditions down the east couloir at 8am.