From its early years, Delta has been the commercial center of one of the largest alfalfa seed and hay producing regions in the Intermountain West. The early 1920s was a time of expansion beyond the limits of productive farmland, stimulated by exceptionally abundant irrigation water and particularly high alfalfa see crop prices. In 1925 the area produced more than one-fourth of the total seed harvested in the entire nation, bringing impressive profits to many growers. By that time, three national seed-packing companies and several local concerns had warehouses and cleaning plants in the Delta area, some of which continued through the difficult years of the 1930s to prosper again later. In the decade of the 1950s, the region produced nearly six percent of the nation's alfalfa see output.

During the Depression years, Delta-vicinity livestock production increased dramatically, enabling many families to survive the difficult period. Such endeavors continued to expand until the early 1960s the Delta Livestock Auction was the second largest in Utah. The local economy received a boost during World War II through employment opportunities for many residents connected with the Japanese relocation camp at nearby Topaz. Although it was part of a shameful episode in the nation's history, many residents remember positive social and cultural interactions with the internees.