This is my own neighborhood so I don’t always think of documenting it: the western edge of the Pleistocene-age alluvial fan, labeled Qpaf (for “Quaternary Pleistocene alluvial fan”) on the geologic map below.
The Broadway lobe consists of two separate hills of this old sediment: Pill Hill on the south and Thermal Hill (as labeled on the 1912 map) on the north. (In a post five years ago I called it Montgomery ridge, after the street running up its crest.) Broadway Creek runs west of Thermal Hill and crosses the gap in the lobe to join Glen Echo Creek. The only spot it isn’t culverted is in the backyards of Brook Street, down near its mouth. It runs right under Tech High and Mosswood Park. Its valley is in the foreground of this photo, looking up 42nd Street past Opal, Manila and Emerald streets toward Broadway. Click the photo for a big version.
The tall trees and associated homes are on the ridge. Behind them is the top of Mountain View Cemetery’s property and its continuation south, and the high hills where Skyline meets Pinehurst. Thermal Hill is modest in comparison, but walk over it, or keep an eye on it as you ride along Broadway, and you’ll know it’s there.
Farther south, 40th Street runs straight over the ridge. You really notice because the rest of 40 Street, all the way to Emeryville, is flat as can be.
Once upon a time the streetcar line punched right through it (the 40th Street cut), and today the original 40th Street, the lefthand one in this view, is named 40th Street Way while the former cut, filled in again, is named 40th Street.