then headed N on the almost level trail.
Much of this trail runs through forest, which gives you a sense of isolation and detachment from the reservoir.
The trail is maintained by the Corps, who have done a great job maintaining the tread and a series of handy footbridges over small streams - all of which were running well in this high water year (
).
The day got off to a foggy start, which created some really moody, noir effects on the lake's waters.
The trail works its way past some trail and lake-accessible campsites at Four Corners Camp and then continues N into the northern-most arm of the lake.
Here, the trail briefly merges with a service road,
and then becomes a trail again - the Rogue River Trail,
as it drops off of the road,
and continues on to the Lost Creek TH on the northern-most arm of the reservoir.
The appearance of a "Rogue River Trail" here might be a bit confusing. The vastly more famous 40 mi long Rogue River Trail (Rogue River TR) is far to the west. The Upper Rogue River Trail (USFS #1034) goes from N of Crater Lake to near the ranger station in Prospect (here). Sullivan (per the updates on his website) now says you can - with some manuvering - make your way from the Lost Creek TH to Prospect {Update: You can, if you're willing to suffer}. Today, we were satisfied to just follow the trail as it headed a bit inland and climbed (very gently) through some oak woodlands on the S side of Fawn Butte,
repleat with well-watered lichens,
to a view E toward the lake.
Then some more travel through the woods,
to our destination for the day - the Blue Grotto - with its 40' waterfall and soft greenish rock, which is ash from Mt. Mazama (now Crater Lake).
After a snack, it was back along the trail,
past an odd tree,
to a detour along the service road,
to Four Corners Camp and a view of the lake - now free of fog and clouds - and then the TH.
A long, but low gain, hike (15.5 mi RT, 600' EG) through some surprisingly pretty meadows and forests to an intriguing waterfall. This feature is more readily accessible from a TH to the E via a 2.5 mi trail and also directly from the lake - we suspect it's a popular destination since it has its own floating restroom moored in the bay.
But today it was all ours... 
I admit, the environs in your Southern OR trip reports really intrigue me. It seems like a strange mix of Eastern Gorge (white oaks, grassy knobs) Eastern hardwood forest, and high desert (madrone, ponderosa, juniper, etc). I really have to get down that way and see for myself.