Most of my geologizing around Oakland is on foot, with the help of the Citymapper phone app and all manner of public transit, which I’ve praised before. In fact, I’ve written a whole compendium of places to see in Oakland this way.

So I’ve gotten to know the AC Transit bus system pretty well. And for accessing lots of interesting, walkable terrain, the 18 line ranks right up there. Recently revised to take up part of the old 33 line, the 18 runs from the bedrock hills and uplands of the Montclair neighborhood to the coastside flats of Albany, with the city centers of Oakland and Berkeley along the way. Plus the Hayward fault.

Here’s the route superimposed on the street map:

^{Route map via gmap-pedometer.com}

and superimposed on the geologic map. (Click either to open it in a new tab.)

^{From USGS MF-2342. Qms, Merritt Sand; Qhaf/Qhl, young alluvial deposits; af, artificial fill; Qmt, Pleistocene marine terrace; Qpaf, ancient gravel of the Fan; Kfn/KJfm, Franciscan sandstone and melange; Jsv, Northbrae Rhyolite.}

I’ll treat the route in two directions, east and north, starting in downtown Oakland by the 19th Street BART station, at Broadway and 20th as shown by the big blue dot. However, every Orange Line station from Lake Merritt to Downtown Berkeley is convenient to it.

The eastern leg of the 18 takes you to central Montclair, a jumping-off point for hikes in all directions. But you start out on central Oakland’s ice-age dunefield underlain by the Merritt Sand. Then you pass the Lake Merritt channel on the 12th Street Bridge, with a fine view of the lake and high hills in all weather conditions.

The bus leaves the lake at the East 18th Street boat landing for a scenic ride through century-old streetcar suburbs, in the ancient gravel hills of the Fan, on Park Boulevard. Watch this unusual street flip as it goes under I-580 from a valley-floor route to a ridge road with views on either side over the glens in Glenview: Trestle Glen and Dimond Canyon.

The route transitions from gravel hills to bedrock where Glenview’s commercial district begins, and the grade of Park Boulevard steepens, leading to the dramatic passage through the peculiar water gap of Dimond Canyon. Once in Montclair it’s easy to visit signs of the Hayward fault, which runs right through the commercial district. Find a place to get a snack and contemplate the many options for geologizing . . . if you haven’t gotten off along the way for another side trip.

Possible side trips from bus stops:
Lake Merritt channel (11th/Jackson Sts)
Clinton Terrace (1st Ave/International Blvd)
Lake Merritt (Lakeshore Ave/E 18th St)
The Fan (Lobe 4): Bella Vista and Haddon Hill (Park Blvd/E 28th St)
Down into Indian Gulch (Park Blvd/Glen Park Rd)
Down into Dimond Park and Dimond Canyon (Park Blvd/Glenfield Ave)
Oakland geology ramble 1 (Park/Leimert Blvds)
St. James Drive slickensides (and EarthCache) (Park/Leimert Blvds)
Upper Castle Canyon via Scout Road (Mountain Blvd/Snake Rd)

^{The St. James Drive slickensides}

Outings from Montclair, some of them ambitious:
Dimond Canyon water gap overview (and EarthCache), Estates Dr/Somerset Rd
Montclair Spur hike
Rocks of Shepherd Canyon
The Hayward fault
To Joaquin Miller Park via geology ramble 1
To Orinda via geology ramble 7
To Rockridge BART via Lake Temescal or geology ramble 8
To Uptown via geology ramble 4

^{Sibley Volcanic Regional Preserve, part of ramble 7}

The northern leg of the 18 gently descends from the ice-age platform around West Grand Avenue and enters a long stretch of the East Bay plain. The route up Martin Luther King Way rises very slowly; only a short jog on 55th Street reveals the notable slope toward the hills. This segment is interesting mostly for the vintage residential districts along the way. I often take afternoon wanders in the plains, but not for the geology.

Shattuck Avenue brings views of the high Oakland Hills over Berkeley; here the road rises a bit more steadily into and through downtown Berkeley and past the Gourmet Ghetto. North of Virginia Street, the route leaves the East Bay Plain and runs through older, more rugged terrain underlain by ancient gravel. Then suddenly you’ve briefly entered bedrock country, where a tunnel was dug for the streetcar line in 1911. The highest point is here at 300 feet elevation.

^{Grotto Rock Park in the north Berkeley hills}

The turn down Solano Avenue reveals the Bay for the first time, but a look to either side tells you something else: like upper Park Boulevard, Solano is a ridge road, descending a ramp of ancient gravel protected from erosion by its connection to Albany Hill, an isolated hump of Franciscan sandstone whose eucalyptus groves were planted long ago to muffle a dynamite factory.

The end of the line at University Village is not far from Albany Hill, the “cerrito” that El Cerrito was named for.

Possible side trips from bus stops:
Lower Temescal Creek and Emeryville (Martin Luther King Way/53rd St)
UC Berkeley campus and downtown Berkeley (Shattuck/University Aves)
Codornices Park (Shattuck Ave/Rose St)
Indian Rock, Mortar Rock and Grotto Rock Parks (Sutter/Hopkins Sts)
The Albany Hill walk (Solano/Kains Aves)

This entry was posted on 13 October 2025 at 7:54 am and is filed under Oakland geology walks. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.