From Omega Underground:
“Today, we at Omega Underground have uncovered the production title for the upcoming Star Wars anthology film featured around Obi-Wan Kenobi. According to a recent listing for Obi-Wan: A Star Wars Story the working title is Joshua Tree. Other recent working titles for Star Wars productions include Space Bears for The Last Jedi and Red Cup for Han Solo (we confirmed back in December).
Why is this working title important?
Joshua Tree (aka desert yucca palm tree) could be hinting to Joshua Tree Nation Park in Southern California (along with other parks) as a possible shooting location for the new anthology film. The original Star Wars shot some Tatooine scenes at Death Valley National Park and surrounding locations. The location tease supports fan speculation that the Kenobi film will indeed take place on Tatooine.
Located primarily in the Southern California Desert with a small portion extending into Nevada, Death Valley National Park covers 3.4 million acres (14,000 km), making it the largest park in the lower 48 states. Within this acreage is an almost complete spectrum of the Earth’s geological eras that are well worth a visit beyond the shooting locations.
In January 1977, George Lucas took a second-unit team to Death Valley to film some leftover pick-up shots that weren’t filmed in Tunisia due to difficulties they had encountered there.
The StarWars website also references U2’s Joshua Tree to Death Valley’s Zabriskie Point, one of the locations for A New Hope.
Zabriskie Point, a famous viewpoint just east of Furnace Creek. Come at dawn for the best lightning of these badlands. Zabriskie Point can also been seen on U2’s Joshua Tree album cover.”