The Needle Creek to Chicago Basin Trail is an old, very-well established and highly used trail. After the first .8 mile, it heads up Needle Creek and gains steadily all the way into Chicago Basin. Compared to many other Weminuche trails, this one is tame. This is the easiest way to reach Chicago Basin if a train ride is in your budget.
From the Needleton footbridge, cross to the east side of the Animas River and follow a trail south for.8 mile to a signed, trail intersection. A trail coming in from the south is the Animas River trail. That's the only foot path way into here if you don't want to pay the train fare. At this intersection, make a left and head up Needle Creek, on the north side of the creek, where the trail stays for the entire journey up to Chicago Basin. At 2.5 miles from the east side of the footbridge, is a trail turnoff for Emerald and Ruby Lakes. Neither the most recent San Juan National Forest map or the Trails Illustrated map show this any longer, but it is on the USGS quad. (This is where the stream from New York Basin comes in on the left.) That would indicate the trail is no longer maintained and may be difficult to spot. There use to be some campsites nearby. If you want to access those lakes now, you're probably better off coming in from Endlich Mesa, because the bottom portion of this trail, as it climbs above Needle Creek, crosses a half dozen avalanche chutes where the trail could have been easily obliterated by now. We are working on seeing if we can obtain any current information on its status.
Beyond where the stream from New York basin comes in, continue another 3.5 miles to the 11,000 ft. elevation in Chicago Basin, where one of the two trails for Columbine Pass heads off to the east. We are designating this as the terminus for the approach. There are campsites well before arriving here and of course, campsites further up in Chicago Basin. We have received reports that beetle kill has devastated the trees here. There has been a campfire ban in place for years. In July and August and even past Labor Day, this area can be crowded with climbers heading for the 14ers. Weekends can be even busier and you can expect competition for campsites. If you have the energy, you may be better off if you can push up either of the two trails toward Columbine Pass and camp at 11,680 ft. where the two trails merge. There are good campsites there.