4/7, Thursday. Our company event finishes at lunch time. After a volunteer shift packing groceries at Second Harvest 1:30-3:30pm (it was intense), I repacked in the office, leaving my laptop behind. Picked up a car at 5pm. It was HOT. Driving out had terrible traffic, especially near Livermore, exacerbated by the construction on I-84. It was hot today, see photo: 93°F. By the time I arrived at Groveland (to use the restroom), it was already after 10pm.
4/8, Friday. The road to Hetch Hetchy is only open 8am-5pm (later in summer). I saw at least two road blocks, not sure which one would be closed at 5pm. Saw 4 deers by the road. I arrived at the national park entrance at 8am. Filled a registration for backpacking. I asked any other options than my tentative plan. The ranger told me that for my 2 nights, this is the best choice. A classic, and I should camp at Vernon Lake and Rancheria. They asked about my bear can. Apparently I could rent one here. (When I called the ranger station a couple of weeks ago, I was told they don't rent bear cans here). They said they'd like me to report the trail condition when I'm done, as they only took over the station last weekend, and hadn't talked to anyone who did the loop. Through the winter, this post is manned by volunteers.
I parked at the overnight parking lot (at least 0.5 mile further away, at the entrance to the walk-in campground). 2 cars were already here. The sites are quite nice, more or less private, each has its own food storage box and picnic table. But I don't see where water is. I changed into hiking boots, chowed down more food, hoisted on my backpack. Another car pulled in. ~9am, already warm. Little shade. From here I walked by a few campsites (all on short side trails) and scrambled down to the day-use parking lot. Elevation ~3800'.
First, I walked along the dam. A few display panels about the history and images before this valley was flooded. Not it provides the drinking water to the SF Bay Area. Boating, swimming, fishing are not allowed here.
Then, a tunnel with dim lights. It's wide enough for cars. The gravel road continues after the tunnel. Not a lot of shade.
About a mile from the Day Use parking lot, it's the first trail junction. I turned left, and up, towards "Beehive - 6.5 mile, Laurel Lake - 7.6 mile, Vernon Lake - 9.9 mile". There were quite some Blue Dick blooming along this first section.
The trail is well made and maintained, zigzags up the otherwise steep slope. South facing, little shade. Saw some Harlequin Lupine (pink). View is nice over the reservoir. You don't want to cut the trail here, because the bushes are very prickly. I don't remember the trail junction after 1.8 miles (at ~5200'). About then, you lost the view, but you are still going up, just more gradually, for another 1000'. It's quite boring for 4+ miles.
I took a photo of the next junction, about 4 miles from the bottom. Then, it's more or less flat. More trees, so more shade. I was running out of drinking water. Finally I saw a snow patch. I was very happy, sat here for lunch, and refill my bottle. It's probably the Beehive Meadow. Not sure why it's called Beehive. Snow sometimes obscured the trail. I do see footprints, but not fresh. Occasionally there're small plastic flags on tree trunks. After lunch, I tried to walk up ~100' in order to see Laurel Lake. But didn't see anything. I continued, instead of visiting the lake.
The trail crests ~7000', and finally less trees, more open scenery. It's the Falls Creek drainage. Quite pretty. Occasionaly a small/shallow pool of blue water or green moss patch on flat granite. This goes on for maybe 1 mile, and then it drops down towards Vernon Lake. This may be my favorite section of the loop.
By the time I reached the lake, it was already 4:30pm. I was ready to stop. Scared 3 deers away, after leaving the trail, over some snow ponds towards the shore. Found a suitable spot close to the west end, instead of going further east. Didn't see any other tent. A quiet evening. Washed and ate. Saw a yellow-ochre salamander. No fish. I didn't bother to put on rainfly. So I could see stars. The half moon didn't set until ~3am. So only a brief window for good stars. The night was surprisingly chilly (compared to the day temperature), and I zipped myself completely in my 20°F bag. Not cold, maybe ~40°F. Elevation ~6600'.
4/9, Saturday.
Got up around sunrise. Read a bit before packing out. It's quite nice here. Backtraced to the main trail. Crossed this bridge. Then I lost the trail briefly. Now the trail goes up, for the next 1000'.
It offers good view of the lake and the surrounding area, and the Falls Creek tumbling down. 
At around 7200', the trail goes into the woods again. The slope eases, but a lot more snow. And then, I saw this pawprint. And again, and again. The prints look more fresh than the footprints I saw yesterday. Seems I was walking behind the bear(s). I unplugged my headphone, so my phone was broadcasting. The trail slowly crests about 7600'. Then there was a meadow and a small creek (should be gone in a month). Then slowly drops another 200'. All the while in a jumble of fallen trees and snow. I lost the trail from time to time. Using GPS to guide. No flags on trees. I never saw the bear.
Finally I reached the edge of the Tiltill Valley. South facing, no more snow. The trail turns east. Open view, more burned trees. Then the trail zigzags down. It's again dry and hot. Then, I could see the inviting meadow in the Tiltill Valley. 
At about 6.4 miles from the bridge, I had lunch in the shade at this meadow. Tiltill Creek is a short distance away. I thought about staying here for the night. Just it's too early.
Crossing the creek is easy, however, after a short walk, I ended in a swap. It looks like a meadow, like in this photo that I took at the beginning of my trouble. The tall grass obscure the shallow water. 
On Caltopo, it's marked as a lake. On the park map, it's marked as a meadow. I made multiple attempts, and got some water into my boots. I realized that the trail on my map goes in the middle of this swamp. I ended going on the outer edge of this swamp, bushwhacking trying to stay high. Finally, slowly, I rounded to the south end of the swamp. At one place, I heard voice. Then I saw some guys sitting on boulders ahead of me. I yelded at them: "how did you get over this?" Answer: "we didn't!". I seriously considered taking off my boots and trying to cross in sandals. Couldn't even find a place to change footware. Finally, after some questionable manouvers, I crawled on to the same boulder. Now I could see better how wet this area was. I took out my socks and laid on the rocks to dry. Chatted with Damian (the "photographer"), Justin (from Twitter), Adam (from San Diego). They also camped at Rancheria.
After the guys left, I waited a bit before continuing. On the walk out, I met a bunch of 20 year olds, and a small snake. After about a mile, a series zigzag drops down towards Rancheria Creek. This is a view of the the water slides and the reservoir.
The camping area marked correctly on Gaia, I saw some tents. I walked around, didn't see the creek close by. So I continued. But didn't find the camping area marked on Caltopo. Back tracked to where all the tents are. At least 3 more groups. I found a site next to a large log. No view whatsoever. There are ants here. I pitched my tent, this time, with rainfly on. Went to wash at the creek. A group of 8-9 20-year olds came to sit in the shallow pool. My nose was bleeding again, I was washing it with cold water. After that, I cooked and eat there. Not a bad view. I went to visit the 3 guys I met at swamp. They are all climbers, mostly rock climbing. One guy has heard about Enchantment Lakes, but none of them has ever seen larch trees with yellow needles. After the visit, I went downstream for more photo opts.
4/10, Sunday.
I planned to drive out by noon, and it's 6.5 miles out. Total is about 29 miles, 6100'. I packed out shortly after 8am. The walk now is straightforward. Very easy. Still ups and downs. A small bridge over the narrow Tiltil Creek. More flowers.
Multiple bridges under Wapama Falls (Falls Creek)'s many braids. 
Wapama Falls is really a delight. It's big, and sprays all over. It is a worthwhile day trip. Saw quite a few day hikers. After this, I overtook a large backpack group (at least 10 people). Met more day hikers. I got lost a bit in the camp area. Got to my car at 11am.
I stopped at the park entrance to relay the trail condition. Different rangers today. They told me another party was doing the same loop.
Stopped at Groveland to use the restroom. A birthday party was at the park, so I didn't feel comfortable to go to men's room to use the sink. The sink at the lady's room has no water. There's a drinking fountain here, so I could fill water.
Minor detour to Modesto to fill gas. $5/gl. I refilled the last gallon near my office at $5.79/gl. Arrive at the office at 4:30. Took a shower, and changed into clean clothes. While I was repacking and drinking a beer from the fridge, I saw our CEO walked by. I said hi. Forgot that he was tested COVID position just Monday (6 days ago). I wasn't wearing a face mask, because I thought I was the only person here. Oh, well.
Returned the car shortly after 5pm (overshot the rental car entrance once). While checking in, I was told that my flight was delayed again for 2 hours (from 10pm to midnight). I was too early to check in my bag. I complained to the agent about the delay, and asked her if there's any earlier flight I could move to. Sure enough, the next flight has one remaining seat, but I had to hurry. The boarding would start shortly, and I still had to go through TSA. Well, I made it. Back home at 10pm! Perfect.
