Little Rock`s "little rock" has had a rocky past, but its history could soon be set in stone. The rock formation on the south shore of the Arkansas River that gave the city its name has been without its identifying plaque since July. That`s when police reported the sign stolen for the third time since 1949. Each time, vandals chiseled away small the plaque from the rock`s surface. Now, the city`s Parks and Recreation Department wants to replace the plaque with a large piece of native granite, engraved with the story of the geologic formation that gave Little Rock its name.