From a roadtrip in the mid 90s. At the time, this was one of the last three
towers in Texas that was still manned by human hand and not a computer.

Tower No. 3 opened in 1902 as the result of passage of a state law governing the
crossing of railroads at grade. All Texas interlocking towers were designated by
numbers assigned by the Texas Railroad Commission.

It was built by the Galveston, Harrisburg & San Antonio Railway to
protect the crossing of the north/south mainline of the San Antonio & Aransas
Pass Railway and the east/west main of the GH&SA at Flatonia. Both roads later
became components of the Southern Pacific.

Parts of Tower No. 3’s manual interlocking remained in use until shortly before
the structure closed on Sept. 30, 1996, just 19 days after Union Pacific acquired
Southern Pacific.