Wednesday Aug 27 I hiked both Little Si and Mount Si. I started at the little Si TH, arriving at 5:50am. Bathrooms were stocked with TP and trash cans were available.
After completing Little Si, I veered left onto the upper Boulder Garden loop trail about 0.5 miles from the little Si TH. From here the trail heads straight up, very steep with some large rocks and roots to be stepped and climbed over. It eventually intersects with old trail which continues to climb steeply up for what feels like a lifetime.
Old trail then intersects with new trail, in which you can complete the climb with 2 large switchbacks OR stay on old trail for another 500 ft ascent push to the top ( I opted for the latter).
Once above treeline, I climbed the trail as far as I could go until the primitive trail picks up again to scramble up haystack, which I did not do today but saw 3 youths successfully do it.
I hiked down new trail till I hit Douglas fir trail near the bottom and took that back to the final 0.3 miles of little si trail.
Overall, my Apple Watch clocked 11.8 miles, 4300 ft for the day.
1) pack in all your water—there is no water source this time of year (I drank 4 liters)
2) use poles if you have them
3) Old trail will make you question your will to live and I don’t recommend trying to hike down this route.
Good luck!

With the heatwave upon us I had thought to go to farther out towards the pass (Melakwa Lake).  But I was reminded by a friend that Denny Creek trail was closed so opted for the Old Si trail.  It offers a great workout and has some varied terrain. I was also trying out a pair of new boots I plan to use in the Dolomites in a couple of weeks.

Arrived at the Little Si main parking lot at 7:15 and it was about 80% full.  Seems most were heading up Little Si, not Mount Si.  I started hiking at 7:30 and kept a moderate pace.  It was about 58 degrees and very nice.  I was already hiking in shorts and sleeveless shirt to just stay cool.  The trail is very dry of course and there is no water (the usual) so I carried 2 Liters.  The forest was cool and I was under the canopy until about 3000 ft.  I felt some sun rays on the back of my neck and knew it would be brutal in the exposed sun.  The breeze was pretty cool on the way up.  I was warm but not oppressively overheated.  I saw 1 person heading down and 3 heading up, each of us glad to be out early.  I stopped at the false summit and had a snack in the shade being mindful of time.  The views were plentiful but you could see haze from the heat in all directions.  Absolutely no bugs all day.  Started down after 10 minutes with the continuous breeze.  At about 1800 ft I could tell the air was getting warmer to breath but I was still in the shade as this trail is great in that regard.  I have gotten in the habit of counting switchbacks to pass the time as there are many on the steep section (like 20).  It was wonderful in the Boulder Garden area as there were little birds singing and chirping and the temps were relatively cool.  I thought alot about the many people I have hiked this trail with over the years but it's mostly been in the snow, not in August.  This was a different kind of journey.  Got to the intersection with the Little Si trail and noted the excellent trail work that has been done.  As it turns out, I'm glad Denny Creek trail was closed because it would have been a scorcher heading to Melakwa Lake today.  And my new boots are awesome (tested on steep ascent and descent, and a variety of rocky areas)

Trail was dusty, the last couple of days of rain probably did it good. No bugs barring one random massive cloud of mosquitoes at like 2400 feet. Saw ghost pipes, Anna’s Hummingbirds, Garter snake, nature was busy. Only saw 4-6 people on my way up, highly recommend Old Trail for this reason.

The recent rains helped since the surface was tight and not too slippery.

hit the trailhead via Little Si at 9am. Minimal hikers on the old trail. Trail a bit dusty, but manageable. Took the old trail down as well to avoid a lot of the crowd on the new trail. Minimal bugs on the trail, but there is an active bee hive at the bend of one of the switchbacks.