The road to the trailhead is in reasonable condition - a couple washouts in the usual places and some larger potholes that made me glad for moderately high clearance (Subaru Outback). But I bet a sedan could make it if you're careful. 
There are approx 10 blow-downs across the trail. Some are easy step-overs, while a couple are more significant and take a few minutes to crawl around. All are passable. The trail was largely snow-free until around 3000 ft, including the backcountry campsites and toilet at 4.75 miles. I was surprised to see that Mackinaw Shelter at approx 6.5 miles has been torn down and is now just a pile of lumber. I guess I haven't been up this drainage in a couple years, so maybe that's old news.
Beyond the (former) shelter, the trail starts to climb more steeply and crosses a snow-covered slope that looked ripe for postholing. I'm sure someone more determined could press on further, but I was content to turn around there. This resulted in approx 13 snow-free miles of river valley wandering, which isn't too bad for mid April.
I'd always thought of this trail as "the way to White Pass/Pilot Ridge/Glacier Peak." But this outing reminded me that it's a gorgeous trail in its own right. There are huge old growth cedars right from the start and at least this time of year, there is plenty of solitude. 

At 1.3 miles from trailhead, there is a mostly-frozen creek you need to ford.  It is iced over, with flowing water seen both underneath the ice and on top of it.  We found this creek impassable.  Other hiker's wouldn't.  Hiking poles and microspikes, in my opinion, could help but aren't the total answer, and the risk of an unwanted glissade to the bottom was too great for us.  Other than that, gorgeous day, trail in good repair, lovely big trees, peek a boo views of peaks, no snow and barely any frost.  Verlot Ranger Station closed for season, by the way, the pass machine is broken, and there was no information posted about trail conditions.

I started hiking at 2:30am to make it to White Mountain for sunrise at 7am. North Fork Sauk trial is very easy to walk in the dark with a headlamp. The switchbacks are mostly easy too, though the last long traverse to where the trail joins the PCT gets a bit more sketchy (narrow and exposed). At White Pass I started following the bootpath to White Mountain. Close to the White Mountain summit I ran into a mountain goat. It took about 4.5 hours to get to White Mountain (with a fairly heavy pack)

The White Mountain sunrise was mostly spectacular to the NW behind me, but not on Glacier Peak because the basin gets not early sun. I think sunset would be better.

I was considering continuing off-trail along the ridge (descending from White Mountain), but it looked a bit more tricky than I would enjoy, so I decided to go back down and follow the Foam Creek trail.

I reached the White Chuck basin at 10:30am. The plan was now to go to Kololo. I used crampons on the White Chuck glacier. The glacier had more crevasses than I anticipipated, but it was all exposed ice so I felt it was pretty safe. I would be a bit more concerned walking on the glacier with thin snow coverage.

The standard route via the White Chuck Glacier leaves the glacier soon to follow rock and permanent snow fields. This was all pretty easy, though I did use crampons (very icy in spots where there was no fresh snow coverage).

Once I headed to the ridge, I briefly wandered over the Suiattle Glacier, but I didn't feel like trying to get to the highest of the Kololo summits, so I went to the west summit. The summit has great views.

I went back over the White Chuck Glacier via the same route and then decided to return via Red Pass. After leaving the basin there is a mostly obvious bootpath leading to the PCT.

There has been some work on the Red Pass - White Pass traverse, but it's still a bit narrow and exposed. I reached the intersection with the North Fork Sauk trail just went it got dark. I was glad to be done with the traverse before dark. I was back at the car at 10:30pm.

The Flickr link below has a GPS track that documents the route except the section to Kololo. It's all on established trails or bootpaths.

I saw 3 people during the day: one Glacier Peak climber with a bivy at White Pass (sorry to wake you up), a trailrunner in the basin heading to Glacier Peak and a backpacker just beyond Red Pass.

Distance: 31 miles, 9900ft gain.

Previous trips to the White Chuck Basin and White Mountain that contain useful information:

• https://www.wta.org/go-hiking/trip-reports/trip_report.2014-09-08.6306583713 - This backpacking trip to the White Chuck Basin has a bit more info on the route.
• https://www.wta.org/go-hiking/trip-reports/trip_report.2016-09-29.9167231078 - This approached White Mountain from the Cady Ridge. This reached White Mountain around the middle of the day, which was a bit better for photos.

Dog and I did a three day, two night trip out to the Glacier Peak Wilderness.

Day One

• Reach North Fork Sauk trailhead at 10am. FS 49 had many a pothole and was washed out at one point, but I got through in a Prius just by being careful. 
• Raining steady and walking through puddles for flat section until Mackinaw shelter, which seems to have collapsed completely just in the last few days. Last report had pictures of it standing up. Good place to fill up water or make camp before the climb
• See no other hikers for 26 switchbacks up a grueling 3400' climb out of the valley. Views reward more and more as fog lifts and rain slows down.
•  Snow starts to fall at 5pm coming into White Pass campground on the PCT. Please avoid camping right at the ridge, as it is being allowed to grow back after years of overuse. Take a short trail down to the campsites just west of the ridge. 
• Cold night and as two inches of snow fall. Not fit for a non-insulated hammock, and sleep is scarce. 

Day Two

• Beautiful snow-covered peaks. Take a lazy morning and start out for White Chuck Glacier on the Foam Creek Trail at 10am.
• Trail is difficult to follow with the snowfall, but it soon starts melting as it heats up, leaving many a puddle. A section of the trail heading towards the ridge at 48°02'35.1"N 121°07'39.6"W features some treacherous ups and downs and the trail can be hard to follow. Be careful!
• Reach as far as a view of White Chuck Glacier, but have to turn back to be able to get down to Mackinaw Shelter tonight to avoid another night in the cold. 
• Hike back to White Pass with gorgeous views of mountains as far as I can see. Snow is gone but for the high peaks, creating a gorgeous contrast of color. My dog makes many passes at marmots along the trail (make sure to keep dogs on leashes, even if they are well behaved!)
• Pack up and hump down switchbacks to camp by Mackinaw Shelter and the North Fork Sauk. 

Day Three

• Hike back to the trailhead under warming sun and old growth forest. 

A crew of hardy dry-siders and I made the trek to the top of Glacier Peak via the North Fork Sauk River trail over three days.

The North Fork Sauk River trail-head was packed when we arrived on Friday night and I was happy we were able to find a parking spot. The trail is in excellent condition and travels through impressive old-growth Doug-fir and Cedar groves for the first mile or two. Many fungi were beginning to fruit. At the collapsed Mackinaw shelter (near mile 6) the trail climbs steeply to the PCT and White Pass where the views really begin. Blue berries were perfectly ripe and we took some well deserved breaks to pick.

MMMMMMmmmm nom nom nom nom!!!

At White Pass we took the climbers trail toward Glacier Peak and camped in the White Chuck Basin. Amazingly beautiful.

Saturday we made the climb to Glacier Peak along with a line of other folks. We roped up for the crevasses on the Cool Glacier but the climb was otherwise uneventful.

<3 Glacier Peak!