The hike to Stone Lake and Upper Lake is somewhat challenging, not technically, just a bit steep in places. I got a late start on this hike, as such I finished this hike after dark and being in September sunset comes earlier. Overall, it was a beautiful day with clear skies and very light breeze.
You must descend off the trail to get to the lakes themselves. They are also rimmed with large boulders, so it can be challenging to get to the shore line of any of the lakes in this chain. Beautiful day, worth doing again in early summer to get more daylight on the hike.