There is some contention as to the origin of the name. Early maps show the area as “Conchilla,” the Spanish word for “seashell.” Since the area was once a part of a vast inland sea, tiny fossilized mollusk shells can be found in just about every remote area. Local lore explains the change in the name from Conchilla to Coachella as a mistake made by the map-makers contracted to transcribe the data supplied by the Southern Pacific Railroad’s survey party. Rather than redraw the expensive maps, the railroad chose to instead begin calling the area by the misspelled name “Coachella” rather than its traditional name “Conchilla.” Some believe that the name Coachella was simply made up, but that theory is rather unlikely.
The coming in 1926 of U.S. Route 99 northward through Coachella and Indio and westward toward Los Angeles more or less along the present route of Interstate 10 helped further open both agriculture, commerce and tourism to the rest of the country. So too did the coming of State Highway 111 in the early 1930s, which cut a diagonal swath through the valley and connected all of its major settlements
The Coachella Valley was popular among celebrities from Frank Sinatra to Dakota Fanning who came and continue to come to enjoy vacations and winter homes in the desert resort community. Also it became a major real estate destination in the 1980s and 1990s, no longer limited to senior citizens, winter residents and retirees. Families with young children and young adults became interested in Palm Springs and surrounding communities for lower cost housing and apartment rents. Palm Springs has become a world-famous tourist attraction.
Source: Wikipedia