Started at West Forks Foss Lake trailhead at 9am. Very Hot day hiking up. Big Heart was a great swim as always. Shortly before Atrium peak many side/ erroneous trails start to appear (assumed from people staying at Big Heart and summiting), recommend GPS w/ trail map. After Atrium peak the trail gets particularly difficult. With overgrowth, scrambling, obstacles, side trails leading off, and later, snow fields.  Lost the trail multiple times.  Got to Chetwoot around 7 PM.  Between Chetwoot and Big Heart we only saw 3 parties; all were either doing the traverse (from Iron Cap Gap) or turning around after failing to traverse. Mosquitos were particularly bad at Chetwoot. Lake still has ice/snow in places. Camped up the hill a bit, found a great tree for a bear hang. There were at least 5 decent camp sites scattered about, with only one other party sharing the lake (on a nice Saturday night!?). One site had a full backpack that looked like it had been sitting for a long time (month?); we didn't like that implication--reported. Didn't use the fly, great cloudless starry view. We suspected it was much colder than the NOAA forecast that night.  Hike out the next morning was a little easier, but still took a few wrong turns. Plenty of water sources on this trail. Overall nice hike, w/ killer views of Lake Angeline from the Atrium ridgeline.  Though the bugs were borderline prohibitive.  Didn't see any large wildlife. No berries/few flowers.  

Bottom line: great views, great swimming (but not Chetwoot), terrible bugs, and do not try this w/out a GPS map. 

Side note: Angeline looked very promising but we did not have the energy to investigate on the way out. 

A Cross Country traverse that is stunningly challenging; including a fourth class scramble to Iron Cap Mountain.  Please do not attempt this route unless you have navigational skills.  Exposed with difficult route finding. Wild and rough landscape. 

Please note: found a full backpack at Chetwoot Lake.  No one arrived to claim this pack which included tent, sleeping bag and gear.  Attempted to report to Skykomish ranger station as concerned there is a missing hiker in the area?

Lost at Chetwoot lake in the same area as the unclaimed backpack:  steripen, black honda automatic key, 2 quart platypus bag.  Please call or text Laura at #206-963-5928

Lastly, the trip ended at the Necklace Valley TH finding numerous car breakins, windows smashed out, broken glass everywhere.  Maddening with the thought that there are no sacred places left. 

We took a variant of the alpine lakes high route over the course of a four day backpacking trip. Strava route link for GPX track below. Bugs were not too bad - we had treated everything we were wearing with permethrin and that really helped.

Day 1 - W Fork Foss TH to small tarn near Chetwoot Lake

Day 2 - Chetwook Lake to Tank Lake

Day 3 - Tank Lake to small campsite in Necklace Valley

Day 4 - Exit via E Fork Foss TH

Day 1

Trail from W Fork Foss through to Big Heart was unremarkable. Some route-finding getting from Big Heart to Chetwoot, but you can mostly follow cairns & a relatively beaten path the entire way to Chetwoot. Beautiful views looking down on Big Heart and Angeline heading out to Chetwoot. There wasn't any water between Big Heart and Chetwoot except a small tarn (marked on the map), so make sure to stock up on water at Big Heart.

Day 2

This was the tricky day. We knew we had two route alternatives - from Chetwoot we could either head up to Iron Cap Lake, or we could go around Azure and Azurite, find the "key ledge", and then head up Iron Cap Pass. We wanted to minimize exposure, and I'm not a climber, so we decided on the second route. There is no trail from Chetwoot to Iron Cap Pass - it's all bushwhacking and route finding. Bring a GPS, and be very comfortable with route finding. We saw no parties beyond Chetwoot lake, it felt very remote.

Getting from Chetwoot to Azure was the more straightforward section of the route. Lots of boulder fields to traverse. Finding the "key ledge" was also relatively straightforward - on our GPS track you can see what we believe is the "key ledge" at the little loop above Azurite. When you are above Azurite, you'll reach a very distinctive overturned tree at about 1390m (the roots are entirely facing you). If you want to avoid anything that feels like a ledge or exposed, head up to your right at this point and you can go above the "key ledge". After the "key ledge" from Azurite to Iron Cap Pass was the crux of the day. Very steep, pine-needle covered forest. Thankfully there were a lot of blueberry bushes we could hold onto. No exposure, but definitely not fun. It certainly felt at places that if you let go of the blueberry you could easily slip about 20 feet down into the forest. Thankfully no devils club. The forest alternates with boulder fields to traverse. Once you've reached the base of Iron Cap Pass you are home free all the way to Tank - heading up Iron Cap Pass is significantly less steep than Aasgard or Headlee Pass & the rocks are very secure. Would recommend filling up water both at Azurite and at one of the little tarns at the base of Iron Cap Pass. After Iron Cap Pass all the streams marked on the map all the way to Tank were either dry or very out of the way of the trail. Stunning views of Summit Chief/ Chimney Rock will greet you at the top of Iron Cap Pass as you head to Tank Lake. 

Day 3

We hung out at Tank most of the day, then the smoke blew in around 6 PM and we decided to head a little lower for hopefully less smoke. We had Tank to ourselves the entire day - amazing swimming. We saw quite a few tadpoles in the lake and a couple marmots. The solitude was nice, and we would have been the only one's camping there Monday night.

We headed down Necklace Valley and passed Opal, Emerald, and Jade lakes. We continued down and camping along the trail at a small campsite about 5 miles from the E Foss trailhead. Heading down from Tank to reach Opal was the most difficult part of the day - it's steep boulder fields with difficult to follow cairns that often dead end. You'll still need to be on your route finding game for this section. Once you hit Opal, it's trail all the way out. 

Day 4

Not much to remark here - walking out on trail from our campsite all the way out to the E Foss TH, then walking 2 miles along the road to the W Foss TH. The last couple miles in the forest are thankfully flat and pass quickly. 

Hiked in through the West Fork Foss River trail past Trout Lake, Copper Lake, Little Heart Lake, Big Heart Lake, and across the ridge between Angeline and Big Heart to near Chetwoot Lake. Trail is snow free with no blowdown the entire way. Quite rocky and drier than usual for late in the summer. Ripe berries everywhere beyond Copper Lake. Continued across Atrium Ridge (the ridge separating Big Heart from Angeline Lakes) to a spot near Chetwoot Lake.

This report is mainly about the section between Big Heart and Iron Cap, and my encounters exiting below.

I did a two night trip up via West Fork TH, planning to explore the southern Foss Lakes area.  I've been up both sides dozens of times (Copper/Big Heart side vs Tank/La Bohn/Hinman side), but for some reason have never done the loop or visited this section.  Since I didn't have a ride between THs and prefer not to walk miles on forest road, I decided it would have to be an out-and-back instead of the loop.

The trail from Big Heart up over the spine between it and Angeline is longer and harder than I expected.  It's not difficult if you have basic navigation and are in decent shape, but because of the popularity of the area I figured it would be worn into a real path pretty much, but it's actually fairly rough.  Signs of 'trail' come and go, but you can't really go wrong following the north-south spine.  There's a lot of up and down, especially on the south end as you near Chetwoot, but the views along the route are great.  

Camped night 1 on a rocky bluff overlooking Angeline and Azure.  Did a little fishing in Azure, which although a small lake, is pretty much a giant trout farm.  Planned to camp night 2 at Tank Lakes, but after exploring route options (aka going up on the south Iron Cap ridge) and realizing the easier route would be to skirt around the north I decided to stay on the saddle just west of the Iron Cap summit.  There were 2-3 sizeable high snow patches still giving a steady faucet drip, which was great because going from lake to lake for water in this area is a lot of up and down.

Barely saw a soul the whole trip, until the exit, when I passed a horde of people camping at Big Heart lake, many of which were camped directly on the trail (I don't think I've had a trip this year that didn't encounter someone camped directly on a trail...) People - There are MANY campsites up and tucked away above and around the lake!  These people clearly don't know or are too lazy to look, but I think they might enjoy their experience more (as would others) if they didn't splay out all their personal belongings along the trail like some mountain yard sale.  It would also be nice if people maybe didn't yell their conversations across the lake?  Common sense.

Passed about a dozen more people further down, half day hikers, one of which brought a dog which was thankfully leashed.  Unthankfully, really enjoys barking.  Really unthankfully, attacked and nearly bit me in the parking lot.  I had to jump out of the way and almost had to kick the dog in the head before the owner called him off.  Good times.

I think the star of the trip was really taking in Angeline Lake.  It's rather hidden from view if you don't do the loop, despite being one of the largest lakes in all the alpine lakes wilderness.  I think you can see it a bit from the Tank Lakes side, but really it's one of the deepest blues you'll ever see, probably from the depth, most of its sides are very steep and generally inaccessible.  There's an overhang view relatively near the Big Heart outlet, looking down at the north end of Angeline, and the surprise color is like a punch in the face.

If you want a quick trip (relative) that has an easy access TH, but still want to get away from all the foot traffic, this area might be for you.