After a bit of searching, the earliest photo of Mt Sutro that I found was from 1892. It is noted to have been taken looking SW from a large dairy farm in the Haight-Ashbury district. Here is the link from the SFPL website:
Another interesting photo I came across (although not Mt Sutro, but related in topic) is one taken of Mt Davidson in 1885. The photo appears after the second paragraph. Here is that link: