Lambert decided to open both caves to the public, although Lookout Mountain Cave was closed in 1935 since it was not very popular with tourists, who were much more impressed with the upper cave. Public tours began in 1930. Electric lights were installed in the cave, making it one of the first commercial caves to be so outfitted. Motorists travelling on I-75 in the 1970s and 1980s were subjected to dozens - maybe hundreds - of billboards along their route with the words SEE RUBY FALLS beginning hundreds of miles north and south of the falls itself. Ruby Falls remains a staple of Chattanooga tourism, operating daily. Ruby Falls is owned by the Steiner family of Chattanooga, Tennessee.