I'm not quite sure why the loop isn't on WTA's drop-down, but it really is a good one.

24.5mi and ~4,900ft of gain takes you from the Greenwater Lakes trailhead all the way up to Noble Knob and Corral Pass via Lost and Echo lakes. 

You could also drive up Corral Pass and start the loop from up there, cutting out the ~5.5mi out-and-back from the Greenwater Lakes trailhead to start the loop. But it's a very pleasant forest with excellent tread.

There isn't much that can't be gleaned from other trip reports to Echo or Lost Lakes, so here are some quick details on the loop:

• Would recommend going CCW - between Corral Pass and the south end of Echo has no tree cover anymore...doing this between 9am and 4pm would be pretty toasty
• Corral Pass to just south of Echo has quite a few blowdowns right now
  • The real damage is actually between Hidden Lake and the southside of Echo Lake...maybe a sizeable blowdown every 1-2 minutes
  • Trail is still there and we didn't drop below 2mph
  • Definitely no camping opportunities near trail in this stretch
    • There are 1 or 2 spurs to Hidden Lake where you can camp outside of deadfall range, just not the best spots
• The W side of the loop (Lost Lake, Quinn Lake, Noble Knob) was far more popular than the E side
  • From Corral Pass to Greenwater Lakes, didn't see anyone (on a holiday weekend, go figure)
  • Seems like a ton of TRs mention how bad the bugs are at Echo vs. Lost

We thought it might be super busy on this holiday but we only ran across a few groups - mostly backpackers looking to camp over the weekend. BUT the "shooting range" a couple of miles down was jammed packed and one could hear the shots (and fireworks) a good two miles in on the trail - much louder than it usually is when folks are out there shooting. I'd probably refrain from going on a Friday holiday again. With that being said, the trail was its usual gorgeous self - and I'll never get over those new, stout bridges - man, what an improvement! Thanks again, trail workers! 

Angry P.S. Come on, LADIES (we know it's you...) pack OUT YOUR TOILET PAPER! It's rude, crude and selfish. What tree wants all your TP at its base? It's so freaking easy, bring a small ziplock and put your TP in it to PACK IT IN, PACK IT OUT. 

The trail was gorgeous. The first 5 miles heading towards Echo Lake were beautiful. The trail was easy to follow.
The last two miles in

The last two miles to Echo Lake were progressively worse with mosquitos until we reached the lake. The mosquitos at the lake were unbearable- swarming clouds. We set up camp thinking they would get better as the temperature dropped or the winds picked up or in the morning. Nope. It was a scene from a horror movie. We couldn’t escape them.
Bug spray has nothing on this nightmare. They don’t care.
We heard Lost Lake was fine. If you are debating which one right now, go to Lost Lake.

Greenwater Lakes is a Northwest gem for  easy access on a paved (nearly all the way) Forest Service road, a smooth, gradually ascending  forested trail  through exceptional groves of old growth timber along a fast running stream to a lake that is truly green. There were only about 10 cars in the parking lot on a Tuesday noon and few people at the lake. The small first lake which is as far as we went  is surrounded by grassy somewhat swampy areas but has  a small beach and camp site area in one corner. One caveat: the trailhead is easy to miss if one does not note the mileage on leaving SR410  the turnoff from the main road is 9.6 miles from SR410. The guides refer to  7330 road on the right but there was no sign on Tuesday. 

Hiked up to camp one night at Echo Lake. As far as the Lost Creek crossing and most of the way up the ridge trail is in great shape, after which things got a little more rustic, lots of tree falls, mostly scramble-overs (none higher than waist-high) and one chest-high duck-under. Expect to throw your hiking pants straight in the laundry when you get home as several of the later falls are charred from the 2017 fire and there's pretty much no way to avoid being coated in soot getting over them. A few trail slides (the worst of which shows signs of work beginning - thanks trail workers!) but enough remaining secure trail width for passage without any feeling particularly perilous. Lots of mosquitoes as I approached the high point of the trail had me worried about the night at camp, but actually seemed to be much worse near the high point (where there is a marshy area in the woods) than down near the lake.

Around Echo Lake the impact of the fire is definitely still felt; even if you camp towards the north end of the lake recommend taking a walk around to the south end (though be prepared for a scramble as the trail is considerably more obstructed than up to that point) to get a look around the ghost forest on the flats. Fascinating look at the varying post-fire ecologies of the more and less burnt areas. (Though side note on that same point, maybe bring your second-best hiking pants, or at least something you don't mind getting soot-stained from climbing over charred windfalls)