The Carbon Glacier/Moraine Park/ Mystic Lake trail is in excellent condition. After the suspension bridge the climb begins, much of it in lovely old growth with limited views until you get to the park at the top. A few very insignificant snow patches linger as you get towards Moraine Park. Flowers are definitely out and we spent a lot of time with the flower book. View of Mt. Rainier and particularly Willis Wall are spectacular. We turned around at the meadow, and didn't have time to climb the ridge overlooing Mystic Lake. Took us about 7 hours round trip. Met lots of Wonderland Trail hikers.
Note that the round trip to Mystic Lake is 15.8 miles, not 12 as the hiking guidebooks say. Twelve round trip is about right for where we got, a very worthwhile destination but we wished we had a little more time to get to the ridge. Also note that there is NO running water at Ipsut Creek Campground or Carbon River Ranger station, so make sure you fill your water bottles before then.