It can be dark here in the redwood forest. The trees are so tall that we don’t get direct sunlight on the house except mid-day in summer. The rest of the time the sun is so low in the sky that we only get the indirect, scattered, tree-filtered light.

Because of how dark it can feel here, previous owners of our log cabin put in a bunch of skylights. This is the skylight above my side of the bed with a view of several tall redwoods.

skylight view of redwood trees

The Beard

Shaved off most of my beard so I can wear a properly fitting n95 mask when I go out for a flu shot. And just when I was really starting to enjoy my out of control covid beard 🙁

Page Mill Road

I’ve been studying this old San Mateo County map that Casey Dunn shared with me. (Thanks Casey!!)

The map is from 1894, about 25 years before our neighborhood was carved out of a larger tract of land owned by a guy named Timothy Hopkins (son of the Central Pacific Railroad co-owner, Mark Hopkins.) You can see Timothy Hopkins, along with the Pescadero Lumber Company, labeled on the map as the prominent landowners in the area that is now Portola Redwoods State Park and Pescadero Creek (County) Park.

One curious feature of this map is that it shows the precise location of William Page’s sawmill, and it was about 900 feet from our house!

William Page was a lumberman from Mayfield (incorporated into Palo Alto in 1925) who, with Hopkins and others, clear cut and milled much of the local redwood forest.

One of Page’s (then) dirt roads, which was used to transport the output of his mill to the San Francisco Bay for shipping, went from what is now Portola Redwoods State Park (which surrounds our little neighborhood) up and over the ridge of the Santa Cruz Mountain range and down into Palo Alto.

That road, called Page Mill Road, is much of my commute to work (in non-pandemic times).

As an unapologetic tree hugger, living under the canopy of the second growth redwood forest, I find it pretty interesting that we are right next to Page’s mill site, an operation that decimated so much of the ancient redwoods, turning them into the shingles and lumber used to build and re-build San Francisco.

section of an old San Mateo County map from the 1860s showing the location of the Page Saw Mill


The CZU Lightning Complex fire is 93% contained and for the first time since the fire started, they have an estimate for the date of total containment: September 20th at 8PM.

Now, containment doesn’t mean extinguished. It simply means that they have established a control line all the way around the fire preventing its spread. The burning and smoke is likely to continue until the rains come.

Nevertheless, this is good progress and welcome news.

Temtop M10

A few people have asked me how we’re measuring our air quality. We’re doing it with an Elitech Temtop M10 air quality monitor that we picked up on Amazon for about $80.

I really like the Temtop M10. It’s a nice size (a tad bigger than a macbook pro power supply) with a clean design and easy feature set. There’s no wifi or apps or anything like that, just a simple unit with a clear LCD screen and single button that lets you cycle through the various readings (AQI, HCHO, PM2.5, and TVOC.) The LED at the top changes colors from green to read depending on the air quality.

This air quality monitor is rechargeable (comes with USB cable) and seems to run for about 5-6 hours on battery but I keep it plugged in except when doing spot checks in other rooms or outside.

You can get this monitor on Amazon for about $80. If you’re only interested in measuring the wildfire smoke, you could probably get the $60 P10 model which is limited to measuring PM.25 particulates and doesn’t measure formaldehyde or volatile organic compounds. (Though I think wood smoke does contain formaldehyde so if that’s a concern, go with the M10 model.)

Temtop air quality monitor reading 4 ug/m3 of PM2.5 particulates

Indoor AQI

My lungs are particularly sensitive to the air quality. I have a chronic lung disease (called sarcoidosis) so it’s important that the air I breathe is as smoke-free as it can be.

Our indoor air quality would normally be about the same as outdoors. We live in a somewhat porous log cabin and there’s lots of opportunity for the outside air to get inside. To combat all the fire smoke, we are using a Blueair Blue Pure 211+ air purifier and a DIY purifier made by taping a MERV 13 HVAC air filter to box fan. As a result, our indoor air quality has remained significantly better than outdoors.

As noted in an earlier post, the outdoor air quality has improved today but over the last couple of weeks it’s been quite awful. Fortunately, our air purifier setup is working pretty well. We’ve been able to keep the indoor PM2.5 levels between 5 and 15 µg/m3 (which corresponds to an AQI of about 20 to 60.)

Most of the time, the indoor air quality has been acceptable, even for someone with underlying health issues like me. Occasionally, when the smoke has been particularly bad outside, our indoor PM2.5 levels get up in the 12-15 range which isn’t as healthy for me so we’ve ordered a second Blue Pure 211+ to put the beat down on any remaining smoke particles.

Today the outdoor air quality is much better than it has been the last couple of weeks and so our purifier setup has had no problem keeping up. Right now our indoor PM2.5 level is 3 µg/m3 or an AQI of about 12 which is completely acceptable.

Bay Area AQI

Today’s air quality in the Bay Area is significantly better than it has been for the last couple of weeks. This is PurpleAir’s map with the AQ&U conversion applied.

San Francisco is looking particularly good (well “moderate” according to the tables.) Except for people with underlying health issues, the SF air should be breathable. It gets a bit worse as you travel down the Peninsula to the South Bay where it gets into unhealthy for sensitive groups, and it’s even worse further south around Santa Cruz where it’s unhealthy for everyone.

Nevertheless, the winds have been in our favor and the air is much better than it has been in recent days and weeks.

PurpleAir's AQI readings for the SF Peninsula

A Wonderful Commute

I live among the redwoods and they are absolutely my favorites of the forest. They’re amazing trees in so many ways. But I love all the native trees in the area and indeed some of my favorite individual trees in the Santa Cruz Mountains are oaks. (Yes, I have favorite trees. Don’t judge me :-)

Pre-pandemic, I commuted several days a week over the mountain to Silicon Valley for work. Most of the mountain part of the drive is through forest. There are a few minutes of chaparral and meadow, but trees dominate.

The drive up the west side to the summit takes about 15 minutes and on it I pass through coast redwoods, Douglas fir, Pacific madrone, California buckeye, California bay laurel, coast live oak, and canyon live oak.

The drive down the east side of the mountain takes about 20 minutes and it starts with some open spaces and then moves back into woods. It’s got scrubby oak and bay laurel bushes, manzanita, and coyote brush and wide open meadows. It’s also got coast live oaks, black oaks, valley oaks, Doug fir, madrone, and buckeye.

There are half a dozen trees on the eastern slope that I call my totems and I that always slow down to appreciate and sometimes stop the car and get out to just hang with for a bit. Three of the totems are oaks.

The first on the drive down the mountain is a gigantic and ridiculously tall coast live oak that must be several hundred years old. The tree is right off the road and surrounded by a beautiful grove of younger oaks that extends part of the way up Black Mountain.

The second totem I pass on my commute is a Pacific madrone. It’s not a giant, but it leans out across the road with orange bark that turns a fiery red in the rain. It really can’t be missed. Then, if that wasn’t enough, the orange bark peels off to reveal a bright satin green. What a show.

Until a few years ago, when it was lost in a storm, my next totem was another great big sprawling coast live oak. It sat alone on a small hill and through its low to the ground branches, I could see a glimpse of the bay. (I sometimes use Google Street View’s time travel feature to revisit it. I miss this tree every time I pass that spot.)

The next one is another coast live oak. This one was, until recently, almost magically proportioned, my Platonic ideal oak tree. Its roots are exposed by the road cut, its central trunk goes up about ten feet and then blossoms into a six or seven symmetrical branches that give it this almost spherical crown. A couple years ago wind or lightning split two of those branches off of the tree. I was worried that who ever owns it would cut it down, but they haven’t and it still stands strong, if a bit less regular.

Then, as I come off the mountain onto the flat, the next of my totems is actually two trees, a pair of large California black oaks that reach out from opposite sides of the road to touch each other. These two black oaks are as spectacular in the fall and the winter, with their grand branches completely visible, as they are in the spring and summer with lush green leaves closing off the space above the road to form a short tunnel.

And the last totem on my commute down the mountain is a California buckeye that blooms *pink*. I pass quite a few buckeyes up and down the mountain, some larger, most about the same size but they typically have white to oat colored flowers while this one has stunning pink flowers. I look forward to seeing it bloom every year.

A few hundred feet later and it’s my first stop light. The nice part of the drive is over.