It’s usually near impossible to narrow down the location of where people picking fruit in photos might be located. Here’s a C.C. Pierce collection shot that gives us something more to work with and helps explain why he also had an image of the related packing house on Santa Monica Boulevard west of Weyse/Vine:
https://calisphere.org/item/7aa293a50a7997064e3820d36b3ec4f1/
Note the fruit crate on the top right which seems to read CAHUENGA VALLEY LEMON EXCHANGE and then COLGROVE CALIF——>>
The photo cropped for the crate detail..
sourced calisphere as above.
So that’s one definite image of the citrus origins in old Colgrove.