Preminger wanted to shoot the entire film in Georgia, and in November and December 1965 he visited the state to scout locations, but a union dispute changed his plans. Because he would be filming during the oppressively hot and humid months of June through August, he planned to shoot at night as much as possible. The New York union, which had jurisdiction over Georgia, demanded crews be paid double for any filming after 4:00pm, an added expense Preminger knew would be prohibitive. Production designer Gene Callahan suggested his home state of Louisiana might be a viable alternative, since the unions there were governed by the more liberal one in Chicago. Baton Rouge and its environs were selected, and Callahan's crew began planting cornfields, erecting shanties, and constructing a dam and reservoir containing 17.5 million gallons of water.