So many blueberries/huckleberries/salmon berries. Added a substantial amount of time with all our berry picking stops :)

The way to Thunder Mountain Lakes is straightforward overall but there are a lot of social trails, talus fields to scramble across, and a few cairns here and there. We tried to pick the paths with the least impact on the fragile heather and meadows.

There are quite a few campsites around the lake but it does look like tents have been pitched on grassy spots around the lake (unfortunately).

We were there on a Sunday-Monday and only 3 groups total staying at the lake but we heard there were around 20 tents Saturday to Sunday! There are quite a few dirt campsites along the way (after the turnoff from the PCT) which can be a good backup if dirt/rock campsites around the lake are full.

Given how rocky it is around the lake and the high volume of visitors, would recommend wag bags for solid waste to pack out.

Beautiful adventure, we’ll visit again in the future I’m sure!

Day-hiked Thunder Mountain from Tunnel Creek trailhead and loved it! From tunnel creek trailhead, follow the trail past Trap Lake (gps map available on AllTrails). 10/10 natural beauty. 4,200 ft elevation gain and took us 8 hours of active time. Started around 9 am. This was my first hike of the season and I don't hike super often (this was my longest hike ever) - I am a moderately active person and think its doable for most moderately active people as long as you pace yourself. Brought about 3 liters of water and a lifestraw just in case I ran out. It was an overcast day but I still drank almost all my water.

Getting to the trail head - pot-holed narrow dirt road (1 car width) up to trailhead, but doable for all vehicles probably if you go slow.

Trailhead - no bathrooms or water. Limited parking on side of road, probably room for 15 ish cars total. Getting there before 9 am on the weekend is a good idea. No trail pass seems to be needed, a free self-issued permit is available at the trailhead.

Trail conditions - only one very small patch of packed snow to cross, no traction devices needed. Otherwise trail is in good condition and easy to follow.

Seasonal info - beautiful fields of wildflowers right now!! Also lots of mosquitoes - drench yourself in bug spray. Soak your feet or take a swim in the lakes at the top - its ice cold but refreshing.

Difficulty - Does not require technical skill. There are 2 boulder fields to cross but probably take about 15 min total to cross. I used a full range of motion to clamber over them but rocks generally seemed big and steady - easier for people with longer legs. There are cairns marking the path but you should download an offline map just in case. I would not recommend this trail for people with a fear of heights as there are several section where the trail is very very narrow and there is a steep drop off to the side. A hiking pole was very helpful for the descent.

Pic of lake is not of the top most lake - could only upload 4 photos

I pulled up at the Trailhead at around 8:45 am. There were around 15 cars parked on the side of the road. This TH does not have a proper Parking Lot, neither it has a Toilet.
the nearest Toilet coming from the Seattle side would be the Iron Goat interpretive trail. otherwise you can head towards the Ski resort area.

The 1.3 mile gravel road has a lot of potholes, but is doable in a sedan.
Only I and a subaru sedan was in the parking lot in the morning, every other car is with higher ground clearance.


The first part of the trail from the TH to Hope Lake is steep, around 1300 ft of climb in 1.5 miles.
then it gets gentle as soon as you're in the PCT.
I ran into 2 PCT southbound hikers at the Trap Pass.
funny conversations we had, I asked them if they are heading to Surprise and Glacier Lakes.
They response was - we will go wherever this trail takes us!
Then they told me they're heading to Mexico. So exciting and fun!


From Trap Pass to the Thunder Mountain Lakes, the trail gets interesting. for sure, it's an unmaintained trail..and I need to do a lot of scrambling over Rocks and tree roots.

after that, the boulder field was short and fun, follow the cairns.
right before entering the Lakes area, there is a small snowfield of 15-20 feet, pretty easy! no postholing as of now.

Thunder Mountain Lakes is absolutely one of its kind, totally worth the slog. I could see the Dip Top peak and Mt Daniel, Hinman ( I think) on the south side, and Glacier Peak, Sloan peak on the north.


This trail is very popular, but not like other Crazy ones. Saw around 30-35 people in the entire trail.
few runners, day hikers, and mostly backpackers!
I'm definitely gonna backpack here one day, just to get sunrise and sunset pictures of the Mt Daniel and Hinman!

it was a long day of hike,
14 miles, 4100 feet of gain!

On my quest to visit all the lakes in the ALW (eventually) I was excited when my partner agreed to go to Square Lake. A fire took out part of the Square Lake trail many, many years ago and trip reports have been scarce since then. He was "least interested" in the 14+ mile trail route from Icicle Creek, and more interested in my other route ideas (via Deception Lakes and via Thunder Mountain Lakes) so we decided to go in one way, bring our packrafts and see a loop option was viable. 

We started at the Surprise Creek trail around 9am in the cool forest. Lunch around 11:30 at Surprise Lake on a nice rock by the shore, then up to to the old abandoned PCT to Surprise Gap shortly afterwards. After another snack break at the gap, we headed downhill on the old PCT. Half a mile or so before the Deception Lakes area I spied a side trail that on my map looked like a viable option on our route, and a distance saver. We took this trail, which was faint in the grassy areas and well defined otherwise, which lead into a large meadowy area with some ancient signage that I had difficulty reading. We assumed it was more popular to hike or camp here when this was the PCT. At this point we didn't see trail, so trended towards the uppermost Deception Lake which had a few short bits of bushwhacking but was mostly off trail hiking. We then stayed right of the lake, steeply up and then traversed along a boulder field, then into the forest to the low point of the ridge between Deception and Square Lakes drainage. At the low point we followed some faint boot/game trail down through what is probably the only gap in the cliffs. It was steep at times but worked nicely to pop us out above Clear Lake. We took talus and heather down to Clear Lake, staying left of the Lake, then trended right along what looked to the the least steep way to Square Lake. 

We found a campsite to the left of the inlet with a marginal tent site. We decided we would look around and decide if this is where we wanted to sleep after we rafted around the lake. 

Rafts inflated and life vests on (ask me how big our packs were!) we circumnavigated Square Lake. It's a big lake so this was about 2.5 miles of paddling. Max fished while I took a side trip to Lake Wolverine. It was a little tricky to land my raft near the old dam/end of the Square Lake trail but I managed to do so near the campsites, which are across the dam from the trail end. The campsites are all in good condition and unsurprisingly they were empty. I crossed the dam on foot and found the Square Lake trail towards Lake Wolverine. There were fresh game tracks in the trail, but no human tracks and although the trail bed is in good condition, it is extremely overgrown. No problem getting to Wolverine, which is very pretty. 

We decided that there wasn't any reason to move all our gear to the trailside campsites so we set up at the far end of the lake, bug nets on for the mosquitoes and small biting flies. Pleasant night listening to the inlet stream, breeze and water lapping on the lake. 

The next morning we set off across the lake again- I managed to land my raft at the talus field "outlet" stream of Milk Lake. Up the talus, then some light bushes and I found myself at shallow Milk Lake. I wasn't too impressed, and after taking a couple photos, headed back to my raft and camp. 

Next we loaded up our rafts with all our gear and rafted across the lake to a prominent talus field leading towards Thunder Mountain and the lakes. It was a little tricky to land here because of tree debris in the water but we managed. After drying our rafts and repacking we headed up the talus, staying on the left out of the biggest rocks until almost to the grassy heather and cliffs. We took a small gap between trees to more talus, then headed up towards what we saw as the only significant passage between cliffs above us- steep heather with occasional veggie belays required. Above this was more talus.  I'd already climbed Thunder Mountain and it wasn't on any lists that Max was interested in so we traversed upwards towards lower Thunder Mountain lake, which I needed to tag. The upper talus field has some truly enormous rocks which makes it difficult to nagivate esp in a large pack. I'd suggest crossing over at a band of trees if you're headed more directly to lower thunder as we were.  From the map and slope angle shading it avoided the dreaded purple/blacks (most steep) by traversing upwards to 6200 or so, then dropping down on very steep meadowy terrain to the lake- this worked nicely and we found ourselves near the outlet of lower Thunder Mountain Lake. 

From the lake we continued up on a series of benches and slabby easy rock steps to Thunder Mountain Lake, where we saw our first people since the PCT near Glacier Lake. There are lots of campsites if you look around, poor lake is definitely becoming trampled. Enjoyed the lake and topped off water before taking the exposed scramble traverse towards Trap Pass. The bootpath has some vague sections that could use additional cairns, a bit of exposure and a couple of small snow patches. 

Route total including all the paddling around, 22 miles 6800 vertical 

Thunder Mountain Lakes via Tunnel Creek Trail, stopped off at Trap Lake on the way back. Beautiful day to be outside! Trailhead had 5 cars at 8am, and 15 at 3:30pm. Road in does have some large holes, definitely a bit worse than a couple years ago. Pretty manageable in high clearance vehicle.

Tunnel Creek Trail: 1.8 miles of up, some parts brushy and some parts rocky, but gotta get to the PCT somehow. Not too bad as long as you take it slow here, as it is one of the steeper parts. Made it to Hope Lake by 8:45, entirely shrouded in clouds and fog. Brush did not get us too wet which was nice.

PCT from Hope Lake to Trap Pass: Still mostly cloudy which was excellent for the gentle climbing up to the pass. Lots of wildflowers across alpine meadows, especially in the small section that winds down before the big kick up to Trap Lake. As we passed Trap Lake, the basin started to clear up while clouds poured over Trap Pass from the West and burned off - fun little microclimate that illustrates how unpredictable the weather can be up here. It's the PCT, so excellent grading and tread - accidentally brought incredibly beat-up running shoes and was fine. Started seeing the alpine animals here, with a very focused Pika eating. Hit Trap Pass at 5.7 miles, with clouds to the West and partly clear skies to the East. Turned onto Thunder Mountain Lakes Trail.

Thunder Mountain Lakes Trail: Definitely a change from the PCT, quickly becomes narrow and windy, also steep in places. Pitches up to get around the shoulder of Nimbus (Mountain? Peak?), gaining 800 more feet in 1.6 miles. Some small blowdowns but all pretty easy to get over/under or through. Further along, the trail becomes rocky and can be hard to follow over talus, but pretty easy with the markers and Gaia. Saw marmots here on the way up and a mountain goat on the way down, very fun. The pass above the lake is an amazing view, and peaks out at 6500 feet of elevation. Thunder Mountain Lake is gorgeous, and very cold! Highly recommend the refreshing swim, but be careful of the temperatures. Lower Thunder Mountain Lake can also be seen down the hill, with Mounts Daniel, Hinman, and Stuart and a tiny corner of Mount Adams in the background. Not many better spots to stop and have lunch.

Trap Lake: Jumped in Trap Lake on the way back, definitely warmer than Thunder Mountain Lake and also a great break. Big leaner log over the trail down to the lake, easy to get around but will be hard to remove with Xcuts.

Garmin logged 14.8 miles and 5000 feet of ascent. Not a whole lots of bugs, couple of mosquitoes when paused but mostly kept down by the breeze. More people, with at least 30 coming in for the weekend while we were exiting. Not sure if there will be enough space at Thunder Mountain Lakes from what I saw. Stay safe out there!