Immediately after getting off the train, one crosses the
Animas River on a good foot bridge. The trail then runs south (right)
for a little less than 1 km to the point where the trail along the
Needle Creek heads east up the valley. There is a trail register near
this point. The trail climbs gently as it stays north of the creek.
This trail is about 10 km long. As it approaches Chicago Basin, there
is a smaller (less heavily used) trail that crosses the creek and heads
for Columbine Pass. Do not take this trail, but continue straight. A bit
further along the trail forks, there is a cairn at this point. The right
fork leads to a good (and popular) area for camping a short distance
further, while the left fork of the trail starts the climb towards
Twin Lakes. After the first hill this (latter) trail reaches a somewhat more
level area, this is the highest possible campsite. There is a sign next
to the trail at this point saying that camping is not permitted higher
up, including anywhere in the Twin Lakes basin. We established our BC
in this area, as high as possible given these regulations.
Second, from Base Camp in Chicago Basin to Mount Eolus:
Follow the trail passed the sign that indicates the camping boundary. Cross
the creek and climb steeply. After a slightly easier slope, the trail again
climbs steeply with a tiny creek immediately on the left hand side. As soon
as the slope again eases, leave the trail (that heads to Twin Lakes) and
ascend the slope going left into the basin under the east face of Eolus.
There is a good trail coming across from Twin Lakes, this trail stays high
under the distinct rocks above (on the right), therefore one should keep
gaining elevation until one reaches this trail. Follow this trail as it
climbs high into the basin, there may be some snow left at the very
end. The trail ends at a broad ledge that goes right and provides a clear
and good passage to an upper basin just below North Eolus. One will arrive
at the west end of this basin, which is also the higher end, there is a small
lake at the eastern end. (This lake was still covered by ice when we
visited.) From this west end, turn left and climb the rock saddle just
left of North Eolus. This climb is easy class 3, there is an even easier
route following some small ledges further to the right. When the ridge
has been gained, walk along it across to Mount Eolus. This passage is
the famous "Catwalk". The ridge is narrow, but quite level and easy to
walk on. When reaching the slopes of Eolus, one should continue the
climb along a system of ledges on the upper east face. We found it easiest
to immediately gain "the second level ledge", by way of an easy scramble
just after reaching the face. However, there are several routes in
this area. The key is to climb up to a higher ledge in a spot where this
is easy. From about half-way up, one should find a shallow "v-shaped"
formation that leads diagonally up towards the left. Scramble up here (easy)
all the way to a "pit" just below a small notch in the ridge. Ascend the
ridge at this point and head right (north) to the highest summit.
Comments: I did this climb with Pål Jørgen, 12 years. We tried to complete a three peak climb the day before, by traversing directly from the Twin Lakes area on a good trail, however, when reaching the broad ledge to the upper basin, we had hail, rain and beginning thunder. The decision to abort and schedule the climb for next morning was easy. We started at 0545, reached the summit at 0745, had a good rest on the top watching two "neighbors" from Boulder crossing the Catwalk, then descended back down to the ridge and climbed North Eolus which was reached at 0900. We then returned to Base Camp at 1000, a total of 4:15.
We subsequently packed camp and hiked back to the Needleton train in the early afternoon. A leisurely walk that took a bit less than three hours.