My book manuscript (now in the copyeditor’s hands) has a chapter about the Fan, our peculiar region of gravel hills that stretches from Pill Hill to Evergreen Cemetery. In the book I refer to it as Oakland’s second level. I briefly recount its human history, starting with the trouble it caused the initial Spanish exploring expeditions (led by Fages in 1770 and 1772 and by Anza in 1776), then go on:
“Today, whether we drive, ride or walk across the second level, we can still see the underlying landscape and picture how it looked to our predecessors. The eastern, uphill side of the Fan, toward the Hayward Fault, is a string of hills of the third level, most of which are bedrock. The downhill side, toward the Bay, is a variegated landscape of low rises and small gaps through which the Bay sparkles and distant mountains across the water loom, in detail or in silhouette as the weather changes.”
What drives this passage is the bit about picturing how things looked to our predecessors. That might sound romantic — and it surely is — but it’s also a basic skill of geologists, especially in the urban setting.
I sometimes think that as I look around at the Fan, I’m craving glimpses of the hills as they appeared to the Ohlones during the thousands of years they were managed as meadows, the way they appeared in the 1850s when the Town was founded. The Ohlones kept the hills clean to support their lifestyle. Today we keep the hills populated and planted in trees to support our lifestyle. Before humans lived in this country at all, during the ice ages and the warm breaks between them, these hills were either oak-bay woods or cold savannah depending on the climate. The best time for geologists was during the Ohlone years, when the Fan was laid bare.
There are no images from that time. We can only imagine how it looked and felt. To illustrate the tools I use, let’s take Haddon Hill, in the heart of the Fan next to Lake Merritt, as an example (specifically, it’s the Haddon segment of Lobe 4).
First there’s the Bache map from 1857. Although it was primarily a navigation map, it showed details of the surrounding land as well, including Haddon Hill.
The physiography isn’t very precise, but the shoreline and roads can be considered reliable.
Second is the digital elevation map (available in the National Map viewer), which strips the buildings and vegetation off the land.
The composite map, made using the transparency slider, is less stark and easier to deal with.
Haddon Hill is a triangular area defined by the lake, the freeway and Park Boulevard. It has two easy avenues through it that go up little valleys, the northern one on Wesley Avenue and the southern one on Athol Avenue. All the other roads tend to be straight and ruthless. If you walk or bicycle here a lot, you know this already.
When Oakland was a tiny town huddled at the foot of Broadway, Haddon Hill had a road running south through it, undoubtedly based on an Ohlone path, that climbed up from Indian Gulch where Wesley tops out, worked along the 100-foot contour and eased over the hill where Haddon Road meets Brooklyn Avenue, then went down into the southern valley where Athol runs today. (The path branching off to the east along the hill’s crest is probably the route Anza took in 1776.) That all changed when the settlers moved in and cars took over everything. Today gravity doesn’t matter as much, and when we read Friar Juan Crespi’s account of traversing the hills here, “which, although they are all treeless and grass-covered, annoyed us very much with their ascents and descents,” maybe we don’t feel it like he did in 1772.
The old road came down Athol from the right in this view north from the intersection of Athol and Newton Avenues.
Finally we get to the geology part.
Qpaf, Pleistocene alluvium (the Fan); Qmt, Pleistocene marine terrace; af, artificial fill
The “Qmt” part is the same marine terrace that runs through Clinton, and I have to say I disagree with the map. I think the terrace extends only to the “P” in “playground.”
Whenever I venture into the Fan, I’m beguiled by the neighborhoods but always look past the homes and landscaping for the wider views. Here are a few examples from 21st-century Haddon Hill. They tend to come in glimpses. This glimpse from across Park Boulevard, at 9th Avenue and E. 28th Street, shows the St. Vartan church, conveniently on Haddon Hill’s highest point, and Grizzly Peak.
This view down Booker Street shows the lower part of Haddon Hill hiding Lake Merritt in front of downtown. Brooklyn Avenue is just visible in front of the Ordway Building.
This view downtown looks down Cleveland Avenue across the Wesley Avenue valley.
And finally, here’s looking across the Athol Avenue valley at St. Vartan from the top of McKinley Avenue.
Wherever you go, smell the roses.
Oakland Geology 
