Director Coppola was determined that each member of the company master the special flavor and feeling of the whole of "Finian's Rainbow" before one single scene was shot. He wanted to develop what he called "an ensemble sense of performance." The solution: an extraordinary five solid weeks of pre-production rehearsal. Then a final test before shooting--a complete performance of the film before a live audience on a studio sound stage.
After that, the picture was off and winging to 18 principal locations, as well as a score of studio sets. To trace the footloose adventuring of Finian McLonergan and friends, the Panavision-Technicolor cameras spanned the continent to shoot scenes from the Statue of Liberty to the Golden Gate Bridge, with waystops at Mount Rushmore and the Grand Canyon. Some of the action swept over the mountains, meadows and woodlands of California. At the Warner Bros-Seven Arts studio, more than nine full acres of backlot were turned into Rainbow Valley town, complete with narrow-gauge railroad, schoolhouse, general store, postoffice and barns.