I came across this picture of the USS California Mainmast salvaged from the ship and used as a makeshift signal tower on land in Hawaii. Here it is being removed in 1950. AI wrote:

"the "basket" mainmast of the battleship USS California (BB-44) was salvaged following the Pearl Harbor attack and reused ashore in Hawaii as a signal tower.

Timeline of the Mainmast's Salvage and ReuseFebruary 1942 (Removal): After being severely damaged and sunk during the December 7, 1941 raid, the USS California settled into the mud of Pearl Harbor. To lighten the ship so it could be successfully refloated, salvage crews cut away and removed the massive cage-style "basket" mainmast on February 13, 1942, using a large floating crane.1942–1950 (Land Use): Instead of being scrapped immediately, the structure was moved onto dry land at Pearl Harbor and repurposed as an active naval signal tower.

1950 (Demolition): The makeshift signal tower served the naval base through the remainder of World War II and the immediate postwar years until it was officially torn down in 1950."