The vast majority of Prospect Avenue was rechristened Hollywood Boulevard in 1910, but a modest portion of the old Prospect still remains. One source says the street was named by onetime prospector (get it?) John Bower. The story goes that Bower purchased some 160 acres in the Cahuenga Valley in 1873 and later sold 120 of those acres to four men – who in turn sold the land to Harvey H. Wilcox in 1886. Wilcox then subdivided the land as a new town called “Hollywood” and the rest is history. I haven’t found any other sources that support or refute this “John Bower named Prospect Avenue” claim, but I can say that Los Angeles had at least three different Prospect Avenues in the late 19th century; this one was first mentioned in the press in 1887. Personally, I think Wilcox named the street while laying out Hollywood.