Two early settlements are part of the early history of Palmdale. Harold was a stop on the Southern Pacific Railroad and was located on the Sierra Highway near Barrel Springs Road. Palmenthal was settled by 50 to 60 Swiss and German families, who were told that when they saw palm trees, they would be close to the Pacific Ocean. Seeing the Joshua trees in Antelope Valley, they mistook them for Palm trees. Close to the year 1900, the railroad station was moved to what is now the center of Palmdale, and the new town inherited a form of the name Palmenthal, which had mostly been abandoned by that time. Almost all the inhabitants of Harold moved to the new townsite.
Palmdale is located in Antelope Valley, an area also called the High Desert, (the elevation being around 2600 feet). Broad and flat, once an ancient seafloor, it is very arid, a problem which drove off many of the original settlers. Looking across the valley, the mountains in the distance are only visible when the air is clear. The California Aqueduct brought water to this area in 1914, after which agriculture became a significant industry.
Today Antelope Valley is home to Edwards Air Force Base, and is sometimes called the Aerospace Capitol of the United States. The Space Shuttle and many other military airplanes have been developed here. As of the 2010 census, Palmdale had a population of 116,670. It immediately adjoins Lancaster, which is just to the north.